Unity in the Church (Why Can't Christians Agree, and How Can We Know Who's Right?)

Introduction

In this article I will look at several topics about which Christian theologians disagree, which are not essentials of the Christian faith but important, nonetheless.

1. The Bible - Which books should be included? 
2. Baptism - Infant baptism; Sprinkling vs. Immersion, Symbolic or Salvific? 
3. Communion/Eucharist - Symbolic or the real presence of Christ?
4. Prayer and Fasting - Is fasting still expected of Christians?
5. Creation - Old Earth or New Earth?
6. Eschatology - When was Revelation written?  Which parts are literal and which are symbolic?

This is not an exhaustive list of such topics, but it includes a number that perplexed me over the years and which I have researched extensively as well as topics that come up frequently in apologetic discussions.

"In essentials unity, in non-essentials liberty, and in all things charity” is a famous quote that sums up the spirit in which I address the questions addressed in this article.

What are the essentials? I would suggest that we turn to the early church, and the Nicene Creed is generally accepted within orthodox Christianity as defining the essentials. This includes the deity of Christ, salvation by God’s grace through Jesus Christ alone, the resurrection of Christ, the Gospel, monotheism and the Trinity (one God in three persons, the Father, Son, and Holy Spirit).

What are the nonessentials? Everything else. That's not to say they aren't important, but your salvation does not depend on what you believe about secondary questions. They are still important, though, because what you believe about these questions can influence how you live your life and the effectiveness of your witness to non-believers. 

Why can't Christians agree?  What is the best approach to answering these questions?

First, let's look at why this is important.

Why Does It Matter?

Unity in the Church

As Christians we are are all part of the Body of Christ and called to a spirit of unity within the church.  

Jesus, at the Last Supper, stressed this point with his disciples.

A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. By this all people will know that you are my disciples, if you have love for one another."

John 13:34-35 (ESV)

In the earliest days of the Church, as recorded in the book of Acts, unity within the church was a defining characteristic.

Now the full number of those who believed were of one heart and soul, and no one said that any of the things that belonged to him was his own, but they had everything in common.

Acts 4:32 (ESV)

In Paul's letters to some of the first churches, as recorded in the New Testament, he stresses the need for unity.

I appeal to you, brothers, by the name of our Lord Jesus Christ, that all of you agree, and that there be no divisions among you, but that you be united in the same mind and the same judgment.
1 Corinthians 1:10 (ESV)

Finally, brothers, rejoice. Aim for restoration, comfort one another, agree with one another, live in peace; and the God of love and peace will be with you.
2 Corinthians 13:11 (ESV)

There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus.

Galations 3:28 (ESV)

I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called, with all humility and gentleness, with patience, bearing with one another in love, eager to maintain the unity of the Spirit in the bond of peace.

Ephesians 4:1-3 (ESV)

Division in the Church

Despite this, over the years, divisions within the Church have arisen, with the following major events:

1. The Oriental Orthodox church broke communion with the other Eastern churches after the Council of Ephesus in AD 431 and the Western church after the Council of Chalcedon in AD 451, primarily over whether Christ has two natures (human and divine) or one nature (human/divine united).
2. The Eastern Orthodox and Roman Catholic churches divided in the Great East-West Schism of 1054, over ecclesiastical, theological, and liturgical differences that had emerged over the preceding centuries.
3. The Protestant Reformation that started in earnest with the publication of the Ninety-five Theses by Martin Luther in 1517 condemning the sale of indulgences, and soon added sola scriptura (rejecting doctrines based on tradition) and sola fide (salvation by faith alone) as key differentiators that led to the establishment of numerous separate denominations. Over centuries since, the western Protestant churches have evolved into over a dozen denominational families comprised of tens of thousands of separate denominations.

The earliest divisions within the church were primarily over the introduction of heretical teachings and corrections by the apostles and their successors.  Those were sorted out through the New Testament epistles as well as the earliest church councils.

Chalcedonian Schism

First major split within the universal Church occurred when the Oriental Orthodox church broke communion with the other Eastern churches after the Council of Ephesus in AD 431 and the Western church after the Council of Chalcedon in AD 451. The basis of the split was a theological difference in understanding Christology.  The Oriental Orthodox hold to the miaphysitite doctrine, that Jesus is the incarnate word, fully divine and fully human, in one nature, while the rest of the Church holds to the dyophysitite doctrine agreed to at the fourth ecumenical council at Chalcedon, which is that two natures, divine and human, co-exist in the unique person of Jesus Christ.  

East-West Schism

The second, and much larger split occured when the Eastern Orthodox and Roman Catholic churches divided in the Great East-West Schism of 1054, over ecclesiastical, theological, and liturgical differences that had emerged over the preceding centuries. Initial differences were primarily cultural, which influenced the theological and liturgical differences that formed.  Most notably, the western church had changed the formula in the Nicene Creed, "We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father" to add "and the Son" without agreement in a Church Council. Also, the eastern church used leavened bread in the Eucharist, while the western church used unleavened bread. The ecclesiastical difference was the more immediate cause, as the bishop of Rome (the Pope) claimed to be the sole successor to Peter and therefore having authority over the other bishops, rather than "first among equals" as the other bishops held.  Still, most Christians were unaware of the split because the split occurred along natural cultural and geographical lines, and it was only much later that the gulf grew wide.  

Protestant Reformation

The third major rupture in the church began as a reform movement that started in earnest with the publication of the Ninety-five Theses by Martin Luther in 1517 condemning the sale of indulgences. The Protestant Reformation, as it came to be known, soon added sola scriptura (rejecting doctrines based on tradition), sola fide (salvation by faith alone), and sola gratia (salvation by grace alone) as key differentiators that led to the establishment of numerous separate denominations. Over centuries since, the western Protestant churches have evolved into over a dozen denominational families comprised of tens of thousands of separate denominations.  The major denominational families have differed along theological lines such as the Eucharist (symbolic or the real presence of Christ?), Calvinist vs Arminian views of balancing the sovereignty of God and the free will of people, etc. Denominations within the major families are largely based on nationality or national origin but more recently splits have occurred along the lines of liberal (modernist) vs conservative (traditional) camps. 

Sola scriptura, sola fide, and sola gratia are important reforms that came out of the Reformation.  

Sola Fide and Sola Gratia

By the time of the Reformation, the western church had begun teaching salivation as faith + works, at least as understood by many, including the priests who joined the reformation movement, instead of the biblical revelation of salvation through faith alone as evidenced by works.

An example of scriptural support for Sola Fide is Galatians 2:16

Yet we know that a person is not justified[a] by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified.

An example of Sola Gratia is Romans 3:23-28

For all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. This was to show God's righteousness, because in his divine forbearance he had passed over former sins. It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus. 

Then what becomes of our boasting? It is excluded. By what kind of law? By a law of works? No, but by the law of faith. For we hold that one is justified by faith apart from works of the law.

Support for works as evidence of faith is James 2:14-26

What good is it, my brothers, if someone says he has faith but does not have works? Can that faith save him? If a brother or sister is poorly clothed and lacking in daily food, and one of you says to them, “Go in peace, be warmed and filled,” without giving them the things needed for the body, what good is that? So also faith by itself, if it does not have works, is dead.

But someone will say, “You have faith and I have works.” Show me your faith apart from your works, and I will show you my faith by my works. You believe that God is one; you do well. Even the demons believe—and shudder! Do you want to be shown, you foolish person, that faith apart from works is useless? Was not Abraham our father justified by works when he offered up his son Isaac on the altar? You see that faith was active along with his works, and faith was completed by his works; and the Scripture was fulfilled that says, “Abraham believed God, and it was counted to him as righteousness”—and he was called a friend of God. You see that a person is justified by works and not by faith alone. And in the same way was not also Rahab the prostitute justified by works when she received the messengers and sent them out by another way? For as the body apart from the spirit is dead, so also faith apart from works is dead.

Sola Scriptura

The Roman Catholic Church places tradition on a three legged stool along with the Bible and the reason as the way that we know the truth.  The Bible is universally understood within Christianity as God's word and a source of truth.  The Catholic church claims that magisterium of the church is the sole arbiter of what the scriptures mean.  In addition, the Tradition of the church, as passed down through the apostolic line through Peter, is of equal value.  Similarly, the Eastern Orthodox church allows for Holy Scripture and Holy Tradition to form the basis for what is doctrinal, and traditional understanding of the meaning of the scriptures passed down from the apostles through the lines of apostolic succession is the safeguard against the introduction of heretical misreadings of scripture.  Within Protestantism, the meaning of the biblical text is left to each believer, with the guidance of the Holy Spirit, to determine what the scriptures mean, and traditions may be useful within the church as far as worship styles and so forth, but not as a source of doctrine.

What is the solution?

Areas of Focus

How can the church come together to resolve the differences that led to divisions and achieve unity of a sort that hasn't existed since the early church?  First, we need to resolve the fundamental differences that formed the foundation of the primary lines of division within the church and are often still held up as the basis for continued division.

The Nature of Christ

The nature of Christ is the basis of the separation of the the rest of Christ's global church.  In recent years there have been attempts to bring the Oriental Orthodox Church and Eastern Orthodox Church back into communion with one other, an important first step.  The difference between the miaphysitite and dyophysitite doctrines is not as great as they seem when explained from the perspective of the Oriental Orthodox.  Does Christ have two natures, divine and human, or one nature, divine and human?  

The Bible doesn't clearly say whether Christ's divinity and humanity coexist as two separate natures or as one combined nature.  This may be as much about how we understand in our limited human capacity, something which is a mystery, as it is about the important fact that Jesus Christ is fully God and fully human, the only perfect sacrifice.  We shouldn't divide over this.

Ecclesiastical Authority

Prior to the Great East-West Schism, the bishop of Rome had long been considered "first among equals" as the direct successor of Peter in leading the Roman church, while the other archbishops still had equal authority and agreed to doctrinal truths by consensus.  The final blow in the political infighting that let to the Great Schism was the Pope assuming the role of the single head of the church with authority over the other bishops. Since then the archbishop of Constantinople has held the role of "first among equals" without asserting similar primacy.  Within Protestantism, some denominations have formed hierarchical leadership structures similar to the older churches, while others have held to congregational leadership.  

The Church does not need a complex hierarchy of national or global leadership that appoints local leadership and dictates liturgical practices, places rules upon members that are not strictly Biblical, and otherwise micromanages the local congregations.  There may be a place for spiritual leadership above the local level who provide general doctrinal oversight to ward off emerging heresies and who can act as representatives at global church councils that may be warranted from time to time, as well as limited administrative leadership that can coordinate among churches for training, ordination, etc. may have a place. Otherwise, local elders overseeing their congregations are best positioned to lead a local flock with intimate understanding of the local culture and people.

The Role of Tradition

The Catholic and Orthodox churches hold Holy Tradition on equal footing with the Bible as a source of doctrine as well as ecclesiastical and liturgical practice. Protestants, on the other hand, claim to hold only to the authority of the Bible, although many, perhaps most, denominations require adherence to their own traditions of ecclesiology, liturgy, and interpretation of the scriptures.  How much weight should tradition hold within the church?  Can we find common ground?

Traditions of liturgical practice can be valuable to form a link with the past and provide for a rich worship experience, but not all churches need to adhere to those practices necessarily.  Traditions that establish doctrines that are not found in scripture should be looked at very closely to determine whether they can be reliably traced back to apostolic teaching that was handed down orally.  The most credible claims of such traditions may be some in the Eastern Orthodox, Oriental Orthodox, and Catholic traditions where all agree.  Otherwise, edicts that have no such foundation should not be considered binding on Christian behavior.  When it comes to understanding the best way to understand the meaning scripture, it should be possible to recognize the role of tradition in looking back to the early church for answers.

The Early Church

One of the most important things to remember when reading the Bible is that it is a collection of books, all inspired by the Holy Spirit, each telling their own story but together presenting the overarching story of God's creation and redemptive plan for humanity. It was written at a time different from ours by many different authors using many different literary styles, some of which may seem familiar today but are unique to the time, place, and circumstances in which they were first recorded. While Christians today have access to the leading of the Holy Spirit in understanding the scriptures, it is still very helpful, in fact vital, to read the scriptures first to understand what the author was communicating to the immediate audience and how. Proper Biblical hermeneutics can best be assured by reading the scriptures as they were intended to be read, through the lens of the original intent, which is aided by understanding the identity of the author (where known), the original intended audience and circumstances behind the writing of the book, the time and place in which the book was written, the literary style of the book, etc.

When it comes to the New Testament, the early church that existed at the time of the writing of the New Testament was generally the audience, and the "church fathers" who succeeded the apostles as leaders of the church in the first few centuries are generally the best sources for insight into how those scriptures would have been understood by the initial audience, and fortunately there are many surviving writings by the church fathers that can be referenced.

In addition, the early church recognized the inspiration of the Holy Spirit in the various books and letters that were collected into the canon of New Testament scripture.  There is disagreement on whether the "deuterocanonical" books (secondary canon) which are intertestamental Jewish writings, should be considered part of the Bible vs the 66 books that are universally agreed to by all orthodox Christians.  This will be dealt with in the next section.

(There is well researched video entitled How the Earliest Christians Worshipped (In their own words) that you may want to watch when you have a couple hours.)

Canonical books

As previously mentioned, the canon of scripture is not in agreement between the branches of the church today, and that needs resolved.

Old Testament

The Old Testament canon had been widely accepted within Judaism in the centuries preceding the appearance of Jesus, and He confirmed their canonicity in referring to them as the God's word.  He quoted numerous scriptures, read from the scriptures in the synagogue, and specifically referred to them as inspired. Below are just a few examples:

“Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. "

Matthew 5:17-18

“So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets."

Matthew 7:12

But when the Pharisees heard that he had silenced the Sadducees, they gathered together. And one of them, a lawyer, asked him a question to test him. “Teacher, which is the great commandment in the Law?” And he said to him, “You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment. And a second is like it: You shall love your neighbor as yourself. On these two commandments depend all the Law and the Prophets.”

Matthew 22:34-40

But what is the entirety of the Old Testament canon? 

Protocanonical Books

There is universal agreement to the protocanonical books of the Hebrew Bible (Tanakh), commonly grouped into four sets:

1. Pentateuch/Torah; Genesis, Exodus, Leviticus, Numbers, Deuteronomy
2. Historical: Joshua, Judges, Ruth, Samuel¹, Kings², Chronicles³, Ezra/Nehemiah⁴, Esther
3. Poetic/Wisdom: Job, Psalms, Proverbs, Ecclesiastes, Song of Songs
4. Prophetic: Isaiah, Jeremiah, Lamentations, Ezekiel, Daniel, The Twelve⁵

Note that there are 24 books in the Tanakh but 39 books of the Old Testament because the Old Testament in Christian Bibles breaks some books into multiple:

¹I Samuel and II Samuel originated as a single book Samuel

²I Kings and II Kings originated as a single book Kings 

³I Chronicles and II Chronicles originated as a single book Chronicles 

⁴Ezra and Nehemiah> originated as a single book Ezra/Nehemiah

⁵The Twelve is a collection of the books referred to as the "minor prophets" due to the short length of each: 

Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah, Malachi

Deuterocanonical Books

There are other books referred to as deuterocanonical ("belonging to the second canon") by some or apocryphal by others.  The Roman Catholic, Eastern Orthodox, Oriential Orthodox and other churches outside of Protestantism accept some or all of these books as additions to canon.  Protestants consider them useful for historical and cultural context, as they date from the period between the testaments (primarily 200 BC to 70 AD).  The Septuagint (the Greek translation quoted by Jesus and the apostles) contains many of these books, although not being part of the Tanakh are no longer held as canon in Judaism.

The books accepted by Roman Catholic and Eastern Orthodox as canonical are Tobit, Judith, Baruch, Letter of Jeremiah, Sirach, 1 Maccabees, 2 Maccabees, Wisdom, and additions to Esther and Daniel.

Canonical only for the Eastern Orthodox Church are also Prayer of Manasseh, 1 Esdras, 2 Esdras, 3 Maccabees, 4 Maccabees and Psalm 151.  These are included because the Eastern Orthodox Church uses the Septuagint as the primary source for Old Testament Canon.  However, the book Psalms of Solomon is still considered apocryphal despite being also present in that translation. 

While there is disagreement on the canonicity of this subset of books, the primary canon of 39 books is agreed to by all Christian churches and are sufficient grounds for agreement on the major doctrines of Christianity.  The deuterocanonical books were accepted by many in the early church as being part of the canon, but there wasn't agreement on which to include, which is why they aren't universally accepted.  Still, a strong argument can be made for including those that agreed to by both the Roman Catholic and Eastern Orthodox churches, as they were accepted universally until the Protestant Reformation and still were in the King James Bible, and the other books accepted by the Eastern Orthodox church were accepted as canon by much of the early church and were present in the translation referenced by Jesus and the Apostles and so can claim some legitimacy.

Taking as an example the primary concern that Martin Luther raised with the books, which was the Catholic Church's teachings on purgatory, which Eastern Orthodox and Protestants reject.  In that example, purgatory is drawn, in part, from the book of 2 Maccabees 12:39–45:

On the next day, as by that time it had become necessary, Judas and his men went to take up the bodies of the fallen and to bring them back to lie with their kinsmen in the sepulchres of their fathers. Then under the tunic of every one of the dead they found sacred tokens of the idols of Jam′nia, which the law forbids the Jews to wear. And it became clear to all that this was why these men had fallen. So they all blessed the ways of the Lord, the righteous Judge, who reveals the things that are hidden; and they turned to prayer, beseeching that the sin which had been committed might be wholly blotted out. And the noble Judas exhorted the people to keep themselves free from sin, for they had seen with their own eyes what had happened because of the sin of those who had fallen. He also took up a collection, man by man, to the amount of two thousand drachmas of silver, and sent it to Jerusalem to provide for a sin offering. In doing this he acted very well and honorably, taking account of the resurrection. For if he were not expecting that those who had fallen would rise again, it would have been superfluous and foolish to pray for the dead. But if he was looking to the splendid reward that is laid up for those who fall asleep in godliness, it was a holy and pious thought. Therefore he made atonement for the dead, that they might be delivered from their sin.

As seen above in verse 45, atonement for the dead was the basis on which the church justified the papal indulgences that drove Martin Luther to post his 95 theses to ignite the Protestant Reformation. The Eastern Orthodox Church also considers 2 Maccabees to be deuterocanonical but rejects the concept of purgatory. Prayers for the dead does not necessarily lead to the existence of purgatory or undermine the sufficiency of Christ's sacrifice once for all. Resolving the disagreements over differences in doctrines on these books could resolve the major concerns with including these books.

The solution could be to include the deuterocanonical books all Bible translations with footnotes indicating the canonicity of the books is uncertain and why.  That would be similar to the way that modern translations still include Mark 16:9-20 because of the historical presence in the King James Version and other early translations prior to the discovery of earlier manuscripts.

New Testament

The books of the New Testament are universally accepted by Christians.  These 27 books consist of the 4 gospels, which document the life, death, and resurrection of Jesus, the history of the early church , pastoral letters from the Apostle Paul to specific churches or people regarding doctrine, behavior, and leadership, general letters from other Apostles to the church at large, and prophecy.

1. Gospels: Matthew, Mark, Luke, John
2. Acts of the Apostles
3. Pauline Epistles: Romans, 1 Corinthians, 2 Corinthians, 3 Corinthians, Galatians, Ephesians, Philippians, Colossians, 1 Thessalonians, 2 Thessalonians, Hebrews*, 1 Timothy, 2 Timothy, Titus, Philemon
4. Catholic (general) Epistles: James, 1 Peter, 2 Peter, 1 John, 2 John, 3 John, Jude
5. Revelation

*Hebrews was long considered to be authored by Paul but is anonymous, and most modern scholars believe it to have been written by a student of Paul's, perhaps Apollos, Aquilla, or Luke.

Criteria

The books of the New Testament were quickly circulating among the churches as the gospel message spread throughout the Roman world and the church was in its infancy. The books were generally accepted as inspired almost immediately and later were formally canonized based on the following criteria:

1. Written by an Apostle or someone that learned from the Apostles and eyewitnesses
2. Accepted by most churches throughout the early Christian world
3. In line with orthodox teaching

Other books often sensationalized in the media as "lost" or "banned from the Bible" were largely from the period after the first century written by Gnostics in the second or third centuries under pseudonyms in order to attempt to gain an air of legitimacy.  These were quickly rejected as false by the church, recognizing their inconsistency with existing teaching and lack of true apostolic or eyewitness authorship.

Earliest

The Pauline epistles were circulating in collected forms by the end of the 1st century AD. Justin Martyr, in the early 2nd century, mentions the "memoirs of the Apostles", which Christians called "gospels", and which were considered to be authoritatively equal to the Old Testament.  This was still within the lifetime of many witnesses as well as people who personally knew the witnesses.

See: https://en.wikipedia.org/wiki/Biblical_canon#Early_Church

Accuracy

The New Testament books were written within the lifetimes of eyewitnesses, both friendly and hostile to Christianity, and so opponents has the opportunity to call out factual errors. In particular, accounts of the crucifixion, burial, and resurrection are well attested, including  the following challenge to any skeptics alive within a couple decades of the event:

For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures, and that he appeared to Cephas, and then to the Twelve. After that, he appeared to more than five hundred of the brothers and sisters at the same time, most of whom are still living, though some have fallen asleep. Then he appeared to James, then to all the apostles, and last of all he appeared to me also, as to one abnormally born.

1 Corinthians 15:3-8

Faithful Transmission and Textual Criticism

How can we know that the version of the Bible we are reading is true to the original manuscripts when the physical originals did not survive?  

First, if we believe that the Bible is God's word to mankind, then we should believe the God would preserve that revelation.  However, skeptics would not trust this alone, and there are other reasons to trust the scholarship employed in ensuring the text matches what was originally written.

Second, we know that the methods used for copying manuscripts were carefully employed to ensure faithful copying. This includes practices such as using letter and word counts to ensure that they match from page to page and discarding and restarting any pages that don't match exactly.  The copyists in most cases were believers in monasteries who had dedicated their lives to the process of faithfully preserving the text of the documents.

Finally, scholars employ the methodology known as textual criticism to discern the original meaning when there is variation among the many available manuscripts.  The vast majority of variation is in spelling, dropped characters, etc. Where the difference is less obvious, comparing the nature of what changed in the versions that are the outliers can reveal that what changed was simply a word substitution.  

There are also cases where earlier manuscripts have been found that can be used to confirm accuracy, as happened with the Dead Sea Scrolls to show how accurate the newer Old Testament manuscripts were. Earlier copies of the Gospel of Mark that were discovered after the King James Version was released, resulting in the discovery that Mark 16:9-20 was not present initially and apparently had been added to fill a presumed gap from the other synoptic gospels (Matthew and Luke) by a well-meaning scribe. Even there, the meaning was not changed.

Church Councils

In addition to establishing and safeguarding the perpetuation of the New Testament scriptures, the early church ensured that the doctrines taught were consistent with the scriptures and the interpretations passed down from the apostles. When significant controversies arose, church councils were convened with attendance from the leaders of the major centers of Christianity across the Roman Empire.

The consensus decisions that emerged from the earliest councils, prior to the divisions that arose after the Great Schism, are very helpful to reference in ensuring that we are still consistent with the understanding that has been with the church since early in her history.

What follows are a list of the ecumenical councils that were called during the period before the Great Schism.  Note that a few that were called but were later rejected due to insufficient participation are called out.  Also, not listed are councils that were called within only one branch of the church.

The Jerusalem Council (~AD 50)

Universally accepted

Acts 15:1-35

The Jerusalem Council

But some men came down from Judea and were teaching the brothers, “Unless you are circumcised according to the custom of Moses, you cannot be saved.” And after Paul and Barnabas had no small dissension and debate with them, Paul and Barnabas and some of the others were appointed to go up to Jerusalem to the apostles and the elders about this question. So, being sent on their way by the church, they passed through both Phoenicia and Samaria, describing in detail the conversion of the Gentiles, and brought great joy to all the brothers. When they came to Jerusalem, they were welcomed by the church and the apostles and the elders, and they declared all that God had done with them. But some believers who belonged to the party of the Pharisees rose up and said, “It is necessary to circumcise them and to order them to keep the law of Moses.”

The apostles and the elders were gathered together to consider this matter. And after there had been much debate, Peter stood up and said to them, “Brothers, you know that in the early days God made a choice among you, that by my mouth the Gentiles should hear the word of the gospel and believe. And God, who knows the heart, bore witness to them, by giving them the Holy Spirit just as he did to us, and he made no distinction between us and them, having cleansed their hearts by faith. Now, therefore, why are you putting God to the test by placing a yoke on the neck of the disciples that neither our fathers nor we have been able to bear? But we believe that we will be saved through the grace of the Lord Jesus, just as they will.”

And all the assembly fell silent, and they listened to Barnabas and Paul as they related what signs and wonders God had done through them among the Gentiles. After they finished speaking, James replied, “Brothers, listen to me. Simeon has related how God first visited the Gentiles, to take from them a people for his name. And with this the words of the prophets agree, just as it is written,

“‘After this I will return,

and I will rebuild the tent of David that has fallen;

I will rebuild its ruins,

     and I will restore it,

that the remnant of mankind may seek the Lord,

    and all the Gentiles who are called by my name,

     says the Lord, who makes these things known from of old.’

Therefore my judgment is that we should not trouble those of the Gentiles who turn to God, but should write to them to abstain from the things polluted by idols, and from sexual immorality, and from what has been strangled, and from blood. For from ancient generations Moses has had in every city those who proclaim him, for he is read every Sabbath in the synagogues.”

The Council's Letter to Gentile Believers

Then it seemed good to the apostles and the elders, with the whole church, to choose men from among them and send them to Antioch with Paul and Barnabas. They sent Judas called Barsabbas, and Silas, leading men among the brothers, with the following letter: “The brothers, both the apostles and the elders, to the brothers who are of the Gentiles in Antioch and Syria and Cilicia, greetings. Since we have heard that some persons have gone out from us and troubled you with words, unsettling your minds, although we gave them no instructions, it has seemed good to us, having come to one accord, to choose men and send them to you with our beloved Barnabas and Paul, men who have risked their lives for the name of our Lord Jesus Christ. We have therefore sent Judas and Silas, who themselves will tell you the same things by word of mouth. For it has seemed good to the Holy Spirit and to us to lay on you no greater burden than these requirements: that you abstain from what has been sacrificed to idols, and from blood, and from what has been strangled, and from sexual immorality. If you keep yourselves from these, you will do well. Farewell.”

So when they were sent off, they went down to Antioch, and having gathered the congregation together, they delivered the letter. And when they had read it, they rejoiced because of its encouragement. And Judas and Silas, who were themselves prophets, encouraged and strengthened the brothers with many words. And after they had spent some time, they were sent off in peace by the brothers to those who had sent them. But Paul and Barnabas remained in Antioch, teaching and preaching the word of the Lord, with many others also.

The First Council of Nicaea (325)

Universally accepted

1. Repudiated Arianism (belief that the Son is distinct from the Father and therefore subordinate to him), declared that Christ is "homoousios with the Father" (the Son is of the same substance as the Father), and adopted the original Nicene Creed
2. Addressed the Quartodeciman controversy by fixing the date of Easter
3. Recognized authority of the sees of Rome, Alexandria and Antioch outside their own civil provinces and granted the see of Jerusalem a position of honor.

The First Council of Constantinople (381)

Universally accepted

1. Repudiated Arianism and Macedonianism (belief that the Holy Spirit was created by the Son and was thus subordinate to the Father and the Son)
2. Declared that Christ is "born of the Father before all time"
3. Revised the Nicene Creed in regard to the Holy Spirit.

The Council of Ephesus (431)

Universally accepted

1. Repudiated Nestorianism, which was based on Nestorius's challenge of the long-used title Theotokos ('God-Bearer') for Mary, which he suggested denied Christ's full humanity, arguing instead that Jesus had two persons (dyoprosopism), the divine Logos and the human Jesus, and instead suggested the title Christotokos ('Christ-Bearer') as more suitable for Mary.
2. Proclaimed the Virgin Mary as the Theotokos ("Birth-giver to God", "God-bearer", "Mother of God")
3. Repudiated Pelagianism, which holds that original sin did not taint human nature and that humans by divine grace have free will to achieve human perfection
4. Reaffirmed the Nicene Creed

The Second Council of Ephesus (449)

Originally convened as an ecumenical council, but no longer recognized as ecumenical and is denounced by Catholics, Eastern Orthodox, and Protestants

1. Received Eutyches as orthodox based on his petition outlining his confession of faith.
2. Deposed Theodoret of Cyrrhus and Ibas of Edessa.
3. Condemned Ibas's Letter to "Maris the Persian" (possibly a misunderstood title, indicating as the receiver a certain Catholicus Dadyeshu, bishop of Ardashir/Ctesiphon between 421-56; this same letter later became one of the Three Chapters).

The Council of Chalcedon (451)

This council is rejected by Oriental Orthodox churches.

1. Repudiated the Eutychian doctrine of monophysitism (holding that Christ had only one nature, divine)
2. Adopted the Chalcedonian Creed, which described the hypostatic union of the two natures of Christ, human and divine
3. Reinstated those deposed at Ephesus in 449, including Theodoret of Cyrus.
4. Restored Ibas of Edessa to his see and declared him innocent upon reading his letter.
5. Deposed Dioscorus of Alexandria
6. Elevated the bishoprics of Constantinople and Jerusalem to the status of patriarchates. 

The Third Council of Ephesus (475)

This council is recognised only by Oriental Orthodox churches (it is not recognized by Catholics, Eastern Orthodox, or Protestants). All the following councils in this list are rejected or at least not explicitly affirmed by Oriental Orthodox churches.

1. Ratified an encyclical of Emperor Basiliscus which repudiated the Council of Chalcedon and particularly the Tome of Leo. 

The Second Council of Constantinople (553)

Accepted by Catholics, Eastern Orthodox, and some protestants

1. Repudiated the Three Chapters as Nestorian
   The Three Chapters were:
   a. The person and writings of Theodore of Mopsuestia
   b. Certain writings of Theodoret of Cyrus
   c. The letter of Ibas of Edessa to Maris
2. Condemned Origen of Alexandria
3. Decreed the theopaschite formula.
   (“...our Lord Jesus Christ who was crucified in the flesh is true God and the Lord of glory and one of the holy Trinity.”)

The Third Council of Constantinople (680–681)

Accepted by Catholics, Eastern Orthodox, and some protestants

1. Repudiated monothelitism (holding that Christ has only one will) and monoenergism (holding that Christ has only one energy), confirming the traditional view that Christ was of two natures, divine and human

The Quinisext Council, also called Council in Trullo (692)

The Ecumenical status of this council was repudiated by the Western churches

1. Addressed matters of discipline (in amendment to the 5th and 6th councils).

The Council of Hieria (754) 

Claimed to be ecumenical but rejected by the Second Council of Nicaea (787), since none of the five major patriarchs were represented in Hieria. However it is preferred over Second Nicea by some Protestants. 

    Condemned the spiritual and liturgical use of iconography as heretical.

The Second Council of Nicaea (787)

Accepted by Catholics, Eastern Orthodox, and some Protestants

1. Restored the veneration of icons (condemned at the Council of Hieria, 754)
2. Repudiated iconoclasm.

Creeds

Nicene Creed (325)

We believe in one God, the Father almighty,

    maker of all things visible and invisible;

And in one Lord, Jesus Christ, the Son of God,

    begotten from the Father, only-begotten,

    that is, from the substance of the Father,

    God from God, light from light,

    true God from true God, begotten not made,

    of one substance with the Father,

    through Whom all things came into being,

    things in heaven and things on earth,

    Who because of us men and because of our salvation came down,

    and became incarnate and became man, and suffered,

    and rose again on the third day, and ascended to the heavens,

    and will come to judge the living and dead,

And in the Holy Spirit.

But as for those who say, There was when He was not,

    and, Before being born He was not,

    and that He came into existence out of nothing,

    or who assert that the Son of God is of a different hypostasis or substance,

    or created, or is subject to alteration or change

    – these the Catholic and apostolic Church anathematizes.

Nicene Creed / Niceno-Constantinopolitan Creed (381)

We believe in one God,

    the Father, the Almighty,

    maker of heaven and earth,

    of all that is seen and unseen.

We believe in one Lord, Jesus Christ,

    the only Son of God,

    eternally begotten of the Father,

    God from God, Light from Light,

    true God from true God,

    begotten, not made,

    consubstantial to the father

    Through him all things were made.

    For us and for our salvation

        he came down from heaven:

    by the power of the Holy Spirit

        he became incarnate from the Virgin Mary,

        and was made man.

    For our sake he was crucified under Pontius Pilate;

        he suffered death and was buried.

        On the third day he rose again

            in accordance with the Scriptures;

        he ascended into heaven

            and is seated at the right hand of the Father.

    He will come again in glory to judge the living and the dead,

        and his kingdom will have no end.

 We believe in the Holy Spirit, the Lord, the giver of life,

    who proceeds from the Father and the Son.

    With the Father and the Son he is worshiped and glorified.

    He has spoken through the Prophets.

    We believe in one holy catholic and apostolic Church.

    We acknowledge one baptism for the forgiveness of sins.

    We look for the resurrection of the dead,

        and the life of the world to come. Amen.

Early beliefs

Baptism

The early church was consistent in her understanding of the role and method of baptism.  The modern church has diverged from this understanding.

1. Baptism was by immersion whenever possible, but sometimes pouring or sprinkling were used.
   
2. Baptism was trinitarian ("in the name of the Father, the Son, and the Holy Spirit")
   
3. Baptism was for the forgiveness of sins

Sprinkling and pouring were rare and only when immersion was not possible. Also, any non-trinitarian formula was rejected.  Finally, baptism was considered to be the moment at which forgiveness was granted, with the exception of when baptism was not possible prior to death, such as the thief on the cross who asked for forgiveness documented in Luke 23:32-43.

Scriptures:

Acts 2:38 (ESV)

And Peter said to them, “Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit."

Acts 8:35-39 (ESV)

Then Philip opened his mouth, and beginning with this Scripture he told him the good news about Jesus. And as they were going along the road they came to some water, and the eunuch said, “See, here is water! What prevents me from being baptized?” And he commanded the chariot to stop, and they both went down into the water, Philip and the eunuch, and he baptized him. And when they came up out of the water, the Spirit of the Lord carried Philip away, and the eunuch saw him no more, and went on his way rejoicing.

Acts 22:16 (ESV)

And now why do you wait? Rise and be baptized and wash away your sins, calling on his name.’

Romans 6:3-6 (ESV)

Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.

For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his. We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin.

Galatians 3:27 (ESV)

For as many of you as were baptized into Christ have put on Christ.

Colossians 2:11-13 (ESV)

In him also you were circumcised with a circumcision made without hands, by putting off the body of the flesh, by the circumcision of Christ, having been buried with him in baptism, in which you were also raised with him through faith in the powerful working of God, who raised him from the dead. And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with him, having forgiven us all our trespasses,

1 Peter 3:20-21 (ESV)

…because they formerly did not obey, when God's patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were brought safely through water. Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ,

Early Christian Theologians

Justin Martyr (100-165 CE)

“Then they are brought by us where there is water, and are regenerated in the same manner in which we were ourselves regenerated.  For, in the name of God, the Father and Lord of the universe, and of our Savior Jesus Christ, and of the Holy Spirit, they then receive the washing with water; for indeed Christ also said, ‘Except ye be born again, ye shall not enter into the kingdom of heaven.’  And for this [baptism] we have learned from the apostles this reason.  Since at our birth we were born without our own knowledge or choice, by our parents coming together, and were brought up in bad habits and wicked training; in order that we may not remain the children of necessity and of ignorance, but may become the children of choice and knowledge, and may obtain in the water the remission of sins formerly committed, there is pronounced over him who chooses to be born again, and has repented of his sins, the name of God the Father … And in the name of Jesus Christ… and in the name of the Holy Ghost… does he who has been enlightened receive his washing.”

“The ‘Constitutions of the Holy Apostles’ also refer to John 3:5. There, the one who refuses to be baptized is to be condemned as an unbeliever, partially on the basis of what Jesus told Nicodemus…. He that, out of contempt, will not be baptized, shall be condemned as an unbeliever, and shall be reproached as ungrateful and foolish. For the Lord says: ‘Except a man be baptized of water and of the Spirit, he shall by no means enter into the kingdom of heaven.’ And again: ‘He that believeth and is baptized shall be saved, but he that believeth not shall be damned.'”

Ignatius (35-107 CE)

“Wherefore also, you appear to me to live not after the manner of men, but according to Jesus Christ, who died for us, in order that, by believing in His death, you may by baptism be made partakers of His resurrection.””

Irenaeus (130-202 CE)

“And dipped himself,” says [the Scripture], “seven times in Jordan.”  It was not for nothing that Naaman of old, when suffering from leprosy, was purified upon his being baptized, but [it served] as an indication to us.  For as we are lepers in sin, we are made clean, by means of the sacred water and the invocation of the Lord, from our old transgressions; being spiritually regenerated as new-born babes, even as the Lord has declared:  “Except a man be born again through water and the Spirit, he shall not enter into the kingdom of heaven.”

Hermas (100-150)

“And I said to him, I should like to continue my questions. Speak on, said he. And I said, I heard, sir, some teachers maintain that there is no other repentance than that which takes place, when we descended into the water and received remission of our former sins.  He said to me, That was sound doctrine which you heard; for that is really the case.

Before a man bears the name of the Son of God he is dead; but when he receives the seal he lays aside his deadness, and obtains life.  The seal, then, is the water: they descend into the water dead, and they arise alive.”

Cyprian (200 CE)

“But what a thing it is, to assert and contend that they who are not born in the Church can be the sons of God! For the blessed apostle sets forth and proves that baptism is that wherein the old man dies and the new man is born, saying, ‘He saved us by the washing of regeneration.’ But if regeneration is in the washing, that is, in baptism, how can heresy, which is not the spouse of Christ, generate sons to God by Christ?”

Theophilus of Antioch (181 CE)

“Moreover, those things which were created from the waters were blessed by God, so that this might also be a sign that men would at a future time receive repentance and remission of sins through water and the bath of regeneration all who proceed to the truth and are born again and receive a blessing from God.”

Chrysostom (347-407 CE)

“Baptism is a cross, and ‘our old self was crucified with him,’ for we were ‘united with him in a death like his’ and again, ‘we were buried therefore with him by baptism unto death.’…For as Christ died on the cross, so do we in baptism, not as the flesh but as to sin. Behold two deaths. He died as to the flesh. In our case, the old self was buried and the new self arose, made conformable to the likeness of his death….For baptism is nothing else than the putting to death of the baptized and his rising again.”

Theodoret of Cyr (393-458 CE) 

“We are buried with him in baptism, and we rise with him, so it is not possible for us to enjoy the gift of baptism again…Our former self was crucified with him in baptism by receiving the type of death…This baptism of ours…is one only, for the reason that it involves the type of the saving passion and resurrection and prefigures for us the resurrection to come.”

Photius (310-393 CE)

“Christ was crucified once for all, and we have been crucified together with him through baptism.”

Resources

What the Early Christians Believed About Baptism (audio)

Early Christian Beliefs: Baptism / Born Again

Communion/Eucharist

Christians today disagree on the practice of Communion, also known own as celebrating the Eucharist. Should it be part of every weekly worship service or only once or twice a year? Is it bread and juice served as a reminder of Christ's sacrifice or something more? 

The early church understood it as a sacrament, much as the Eastern Orthodox, Roman Catholic  Oriental Orthodox, and some Protestant churches do today.  There is not agreement on whether this involves transubstantiation or consubstantiation, but I would contend that debating the process is missing the point. Just as there are other mysteries that God has not fully revealed to us, the Eucharist is a mystery that we may not be able to fully comprehend, but we can instead focus on celebrating our participation in this sacred mystery. 

One of the criticisms raised by the Protestant reformers who rejected the traditional understanding of the Eucharist was that it involved ongoing sacrifice of Christ, as if the original sacrifice was not sufficient. Certainly that would be a concern. However, it need not be understood that way.  Rather, it seems better to understand it as one means by which God's grace is imparted to us, as he blesses us for our obedience to his command through participation in the sacrament that Jesus instituted at the Last Supper. 

It could be summarized as follows:

1. Communion is sacred and brings life
2. The bread and wine contain the real presence of Christ for those who believe
3. This is not ongoing, repeated sacrifice of Christ but a means of delivering grace to believers

Let's look at the scriptures and the early church teaching on this subject. 

Scriptures

John 6:53-58 (ESV)

So Jesus said to them, “Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever feeds on my flesh and drinks my blood has eternal life, and I will raise him up on the last day. For my flesh is true food, and my blood is true drink. Whoever feeds on my flesh and drinks my blood abides in me, and I in him. As the living Father sent me, and I live because of the Father, so whoever feeds on me, he also will live because of me. This is the bread that came down from heaven, not like the bread the fathers ate, and died. Whoever feeds on this bread will live forever.” 

1 Corinthians 10:16-17 (ESV)

The cup of blessing that we bless, is it not a participation in the blood of Christ? The bread that we break, is it not a participation in the body of Christ? Because there is one bread, we who are many are one body, for we all partake of the one bread.

1 Corinthians 11:23-27 (ESV)

For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, and when he had given thanks, he broke it, and said, “This is my body, which is for you. Do this in remembrance of me.” In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” For as often as you eat this bread and drink the cup, you proclaim the Lord's death until he comes.

Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty concerning the body and blood of the Lord.

Early Christian Theologians

Ignatius of Antioch

"Consider how contrary to the mind of God are the heterodox in regard to the grace of God which has come to us. They have no regard for charity, none for the widow, the orphan, the oppressed, none for the man in prison, the hungry or the thirsty. They abstain from the Eucharist and from prayer, because they do not admit that the Eucharist is the flesh of our Savior Jesus Christ, the flesh which suffered for our sins and which the Father, in His graciousness, raised from the dead."

    - "Letter to the Smyrnaeans", paragraph 6. circa 80-110 A.D.

"Come together in common, one and all without exception in charity, in one faith and in one Jesus Christ, who is of the race of David according to the flesh, the son of man, and the Son of God, so that with undivided mind you may obey the bishop and the priests, and break one Bread which is the medicine of immortality and the antidote against death, enabling us to live forever in Jesus Christ."

    -"Letter to the Ephesians", paragraph 20, c. 80-110 A.D.

"I have no taste for the food that perishes nor for the pleasures of this life. I want the Bread of God which is the Flesh of Christ, who was the seed of David; and for drink I desire His Blood which is love that cannot be destroyed."

    -"Letter to the Romans", paragraph 7, circa 80-110 A.D.

Justin Martyr

"This food we call the Eucharist, of which no one is allowed to partake except one who believes that the things we teach are true, and has received the washing for forgiveness of sins and for rebirth, and who lives as Christ handed down to us. For we do not receive these things as common bread or common drink; but as Jesus Christ our Savior being incarnate by God's Word took flesh and blood for our salvation, so also we have been taught that the food consecrated by the Word of prayer which comes from him, from which our flesh and blood are nourished by transformation, is the flesh and blood of that incarnate Jesus."

    "First Apology", Ch. 66, inter A.D. 148-155.

Irenaeus of Lyons

"[Christ] has declared the cup, a part of creation, to be his own Blood, from which he causes our blood to flow; and the bread, a part of creation, he has established as his own Body, from which he gives increase to our bodies."

     -Against Heresies, 180 A.D.:

"So then, if the mixed cup and the manufactured bread receive the Word of God and become the Eucharist, that is to say, the Blood and Body of Christ, which fortify and build up the substance of our flesh, how can these people claim that the flesh is incapable of receiving God's gift of eternal life, when it is nourished by Christ's Blood and Body and is His member? As the blessed apostle says in his letter to the Ephesians, 'For we are members of His Body, of His flesh and of His bones' (Eph. 5:30). He is not talking about some kind of 'spiritual' and 'invisible' man, 'for a spirit does not have flesh an bones' (Lk. 24:39). No, he is talking of the organism possessed by a real human being, composed of flesh and nerves and bones. It is this which is nourished by the cup which is His Blood, and is fortified by the bread which is His Body. The stem of the vine takes root in the earth and eventually bears fruit, and 'the grain of wheat falls into the earth' (Jn. 12:24), dissolves, rises again, multiplied by the all-containing Spirit of God, and finally after skilled processing, is put to human use. These two then receive the Word of God and become the Eucharist, which is the Body and Blood of Christ."

    -"Five Books on the Unmasking and Refutation of the Falsely Named Gnosis". Book 5:2, 2-3, circa 180 A.D. 

"For just as the bread which comes from the earth, having received the invocation of God, is no longer ordinary bread, but the Eucharist, consisting of two realities, earthly and heavenly, so our bodies, having received the Eucharist, are no longer corruptible, because they have the hope of the resurrection."

    -"Five Books on the Unmasking and Refutation of the Falsely named Gnosis". Book 4:18 4-5, circa 180 A.D.

Serapion of Antioch

"'Holy, holy, holy Lord Sabaoth, heaven and earth is full of Your glory.' Heaven is full, and full is the earth with your magnificent glory, Lord of Virtues. Full also is this Sacrifice, with your strength and your communion; for to You we offer this living Sacrifice, this unbloody oblation.,

To you we offer this bread, the likeness of the Body of the Only-begotten. This bread is the likeness of His holy Body because the Lord Jesus Christ, on the night on which He was betrayed, took bread and broke and gave to His disciples, saying, 'Take and eat, this is My Body, which is being broken for you, unto the remission of sins.' On this account too do we offer the Bread, to bring ourselves into the likeness of His death; and we pray: Reconcile us all, O God of truth, and be gracious to us. And just as this Bread was scattered over the mountains and when collected was made one, so too gather Your holy Church from every nation and every country and every city and village and house and make it one living Catholic Church.,

We offer also the cup, the likeness of His Blood, because the Lord Jesus Christ took the cup after He had eaten, and He said to His disciples, 'Take, drink, this is the new covenant, which is My Blood which is being poured out for you unto the remission of sins.' For this reason too we offer the chalice, to benefit ourselves by the likeness of His Blood. O God of truth, may Your Holy Logos come upon this Bread, that the Bread may become the Body of the Logos, and on this Cup, that the Cup may become the Blood of the Truth. And make all who communicate receive the remedy of life, to cure every illness and to strengthen every progress and virtue; not unto condemnation, O God of truth, nor unto disgrace and reproach!,

For we invoke You, the Increate, through Your Only-begotten in the Holy Spirit. Be merciful to this people, sent for the destruction of evil and for the security of Your Church. We beseech You also on behalf of all the departed, of whom also this is the commemoration: - after the mentioning of their names: - Sanctify these souls, for You know them all; sanctify all who have fallen asleep in the Lord and count them among the ranks of Your saints and give them a place and abode in your kingdom. Accept also the thanksgiving of Your people and bless those who offer the oblations and the Thanksgivings, and bestow health and integrity and festivity and every progress of soul and body on the whole of this Your people through your Only-begotten Jesus Christ in the Holy Spirit, as it was and is and will be in generations of generations and unto the whole expanse of the ages of ages. Amen.",

    -"The Sacramentary of Serapion, Prayer of the Eucharistic Sacrifice" [13],

Ephrem of Syria

"Our Lord Jesus took in His hands what in the beginning was only bread; and He blessed it, and signed it, and made it holy in the name of the Father and in the name of the Spirit; and He broke it and in His gracious kindness He distributed it to all His disciples one by one. He called the bread His living Body, and did Himself fill it with Himself and the Spirit.,

And extending His hand, He gave them the Bread which His right hand had made holy: 'Take, all of you eat of this; which My word has made holy. Do not now regard as bread that which I have given you; but take, eat this Bread, and do not scatter the crumbs; for what I have called My Body, that it is indeed. One particle from its crumbs is able to sanctify thousands and thousands, and is sufficient to afford life to those who eat of it. Take, eat, entertaining no doubt of faith, because this is My Body, and whoever eats it in belief eats in it Fire and Spirit. But if any doubter eat of it, for him it will be only bread. And whoever eats in belief the Bread made holy in My name, if he be pure, he will be preserved in his purity; and if he be a sinner, he will be forgiven.' But if anyone despise it or reject it or treat it with ignominy, it may be taken as certainty that he treats with ignominy the Son, who called it and actually made it to be His Body.",

    -"Homilies" 4,4 ca.. 350 A.D.,

"After the disciples had eaten the new and holy Bread, and when they understood by faith that they had eaten of Christ's body, Christ went on to explain and to give them the whole Sacrament. He took and mixed a cup of wine. The He blessed it, and signed it, and made it holy, declaring that it was His own Blood, which was about to be poured out….Christ commanded them to drink, and He explained to them that the cup which they were drinking was His own Blood: 'This is truly My Blood, which is shed for all of you. Take, all of you, drink of this, because it is a new covenant in My Blood, As you have seen Me do, do you also in My memory. Whenever you are gathered together in My name in Churches everywhere, do what I have done, in memory of Me. Eat My Body, and drink My Blood, a covenant new and old.",

    -"Homilies" 4,6 ca. 350 A.D.

Athanasius of Alexandria

"'The great Athanasius in his sermon to the newly baptized says this:' You shall see the Levites bringing loaves and a cup of wine, and placing them on the table. So long as the prayers of supplication and entreaties have not been made, there is only bread and wine. But after the great and wonderful prayers have been completed, then the bread is become the Body, and the wine the Blood, of our Lord Jesus Christ. 'And again:' Let us approach the celebration of the mysteries. This bread and this wine, so long as the prayers and supplications have not taken place, remain simply what they are. But after the great prayers and holy supplications have been sent forth, the Word comes down into the bread and wine - and thus His Body is confected.",

    -"Sermon to the Newly Baptized" ante 373 A.D.,

Cyril of Jerusalem

"`I have received of the Lord that which I also delivered unto you, that the Lord Jesus, the same night in which He was betrayed, took bread, etc. [1 Cor. 11:23]'. This teaching of the Blessed Paul is alone sufficient to give you a full assurance concerning those Divine Mysteries, which when ye are vouchsafed, ye are of (the same body) [Eph 3:6] and blood with Christ. For he has just distinctly said, (That our Lord Jesus Christ the same night in which He was betrayed, took bread, and when He had given thanks He brake it, and said, Take, eat, this is My Body: and having taken the cup and given thanks, He said, Take, drink, this is My Blood.) [1 Cor. 2:23-25] Since then He Himself has declared and said of the Bread, (This is My Body), who shall dare to doubt any longer? And since He has affirmed and said, (This is My Blood), who shall ever hesitate, saying, that it is not His blood?

    -"Catechetical Lectures [22 (Mystagogic 4), 1]

"Therefore with fullest assurance let us partake as of the Body and Blood of Christ: for in the figure of Bread is given to thee His Body, and in the figure of Wine His Blood; that thou by partaking of the Body and Blood of Christ, mightest be made of the same body and the same blood with Him. For thus we come to bear Christ in us, because His Body and Blood are diffused through our members; thus it is that, according to the blessed Peter, (we become partaker of the divine nature.) [2 Peter 1:4]

    -"Catechetical Lectures [22 (Mystagogic 4), 3]

"Contemplate therefore the Bread and Wine not as bare elements, for they are, according to the Lord's declaration, the Body and Blood of Christ; for though sense suggests this to thee, let faith stablish thee. Judge not the matter from taste, but from faith be fully assured without misgiving, that thou hast been vouchsafed the Body and Blood of Christ.

    -"Catechetical Lectures [22 (Mystagogic 4), 6]"

"9. These things having learnt, and being fully persuaded that what seems bread is not bread, though bread by taste, but the Body of Christ; and that what seems wine is not wine, though the taste will have it so, but the Blood of Christ; and that of this David sung of old, saying, (And bread which strengtheneth man's heart, and oil to make his face to shine) [Ps. 104:15], `strengthen thine heart', partaking thereof as spiritual, and `make the face of thy soul to shine'. And so having it unveiled by a pure conscience, mayest thou behold as in a glass the glory of the Lord, and proceed from glory to glory [2 Cor. 3:18], in Christ Jesus our Lord:--To whom be honor, and might, and glory, for ever and ever. Amen."

    -Mystagogic Catechesis 4,1, c. 350 A.D.:

"After this you hear the singing which invites you with a divine melody to the Communion of the Holy Mysteries, and which says, 'Taste and see that the Lord is good.' Do not trust to the judgement of the bodily palate - no, but to unwavering faith. For they who are urged to taste do not taste of bread and wine, but to the antitype, of the Body and Blood of Christ."

    -"Mystagogic Catecheses 5 23, 20 ca. 350 A.D

"Keep these traditions inviolate, and preserve yourselves from offenses. Do not cut yourselves off from Communion, do not deprive yourselves, through the pollution of sins, of these Holy and Spiritual Mysteries."

    -"Mystagogic Catechesis [23 (Mystagogic 5), 23]"

Hilary of Poiters

"When we speak of the reality of Christ's nature being in us, we would be speaking foolishly and impiously - had we not learned it from Him. For He Himself says: 'My Flesh is truly Food, and My Blood is truly Drink. He that eats My Flesh and drinks My Blood will remain in Me and I in him.' As to the reality of His Flesh and Blood, there is no room left for doubt, because now, both by the declaration of the Lord Himself and by our own faith, it is truly the Flesh and it is truly Blood. And These Elements bring it about, when taken and consumed, that we are in Christ and Christ is in us. Is this not true? Let those who deny that Jesus Christ is true God be free to find these things untrue. But He Himself is in us through the flesh and we are in Him, while that which we are with Him is in God."

    -"The Trinity" [8,14] inter 356-359 A.D.

Basil the Great

"What is the mark of a Christian? That he be purified of all defilement of the flesh and of the spirit in the Blood of Christ, perfecting sanctification in the fear of God and the love of Christ, and that he have no blemish nor spot nor any such thing; that he be holy and blameless and so eat the Body of Christ and drink His Blood; for 'he that eateth and drinketh unworthily, eateth and drinketh judgement to himself.' What is the mark of those who eat the Bread and drink the Cup of Christ? That they keep in perpetual remembrance Him who died for us and rose again."

    -"The Morals" Ch. 22

"He, therefore, who approaches the Body and Blood of Christ in commemoration of Him who died for us and rose again must be free not only from defilement of flesh and spirit, in order that he may not eat drink unto judgement, but he must actively manifest the remembrance of Him who died for us and rose again, by being dead to sin, to the world, and to himself, and alive unto God in Christ Jesus, our Lord."

    -"Concerning Baptism" Book I, Ch. 3.

"To communicate each day and to partake of the holy Body and Blood of Christ is good and beneficial; for He says quite plainly: 'He that eats My Flesh and drinks My Blood has eternal life.' Who can doubt that to share continually in life is the same thing as having life abundantly? We ourselves communicate four times each week, on Sunday, Wednesday, Friday, and Saturday; and on other days if there is a commemoration of any saint."

    -"Letter to a Patrician Lady Caesaria" [93] ca. 372 A.D.

Epiphanius of Salamis

"We see that the Saviour took [something] in His hands, as it is in the Gospel, when He was reclining at the supper; and He took this, and giving thanks, He said: 'This is really Me.' And He gave to His disciples and said: 'This is really Me.' And we see that It is not equal nor similar, not to the incarnate image, not to the invisible divinity, not to the outline of His limbs. For It is round of shape, and devoid of feeling. As to Its power, He means to say even of Its grace, 'This is really Me.'; and none disbelieves His word. For anyone who does not believe the truth in what He says is deprived of grace and of a Savior."

    -"The Man Well-Anchored" [57] 374 A.D.

Gregory of Nyssa

"Rightly then, do we believe that the bread consecrated by the word of God has been made over into the Body of the God the Word. For that Body was, as to its potency bread; but it has been consecrated by the lodging there of the Word, who pitched His tent in the flesh."

    -"The Great Catechism [37: 9-13]"

"He offered Himself for us, Victim and Sacrifice, and Priest as well, and 'Lamb of God, who takes away the sin of the world.' When did He do this? When He made His own Body food and His own Blood drink for His disciples; for this much is clear enough to anyone, that a sheep cannot be eaten by a man unless its being eaten be preceded by its being slaughtered. This giving of His own Body to His disciples for eating clearly indicates that the sacrifice of the Lamb has now been completed."

    -"Orations and Sermons" [Jaeger: Vol 9, p. 287] ca. 383 A.D.

"The bread is at first common bread; but when the mystery sanctifies it, it is called and actually becomes the Body of Christ."

    -"Orations and Sermons" [Jaeger Vol 9, pp. 225-226] ca. 383 A.D.

John Chrysostom

"When the word says, 'This is My Body,' be convinced of it and believe it, and look at it with the eyes of the mind. For Christ did not give us something tangible, but even in His tangible things all is intellectual. So too with Baptism: the gift is bestowed through what is a tangible thing, water; but what is accomplished is intellectually perceived: the birth and the renewal. If you were incorporeal He would have given you those incorporeal gifts naked; but since the soul is intertwined with the body, He hands over to you in tangible things that which is perceived intellectually. How many now say, 'I wish I could see His shape, His appearance, His garments, His sandals.' Only look! You see Him! You touch Him! You eat Him!"

    -"Homilies on the Gospel of Matthew" [82,4] 370 A.D.

"It is not the power of man which makes what is put before us the Body and Blood of Christ, but the power of Christ Himself who was crucified for us. The priest standing there in the place of Christ says these words but their power and grace are from God. 'This is My Body,' he says, and these words transform what lies before him."

    -"Homilies on the Treachery of Judas" 1,6; d. 407 A.D.:

"'The cup of blessing which we bless, is it not communion of the Blood of Christ?' Very trustworthily and awesomely does he say it. For what he is saying is this: 'What is in the cup is that which flowed from His side, and we partake of it.' He called it a cup of blessing because when we hold it in our hands that is how we praise Him in song, wondering and astonished at His indescribable Gift, blessing Him because of His having poured out this very Gift so that we might not remain in error, and not only for His having poured out It out, but also for His sharing It with all of us."

    -"Homilies on the First Letter to the Corinthians" [24,1] ca. 392 A.D.

Ambrose of Milan

"You perhaps say: 'My bread is usual.' But the bread is bread before the words of the sacraments; when consecration has been added, from bread it becomes the flesh of Christ. So let us confirm this, how it is possible that what is bread is the body of Christ. By what words, then, is the consecration and by whose expressions? By those of the Lord Jesus. For all the rest that are said in the preceding are said by the priest: praise to God, prayer is offered, there is a petition for the people, for kings, for the rest. When it comes to performing a venerable sacrament, then the priest uses not his own expressions, but he uses the expressions of Christ. Thus the expression of Christ performs this sacrament."

    -"The Sacraments" Book 4, Ch.4:14.

"Let us be assured that this is not what nature formed, but what the blessing consecrated, and that greater efficacy resides in the blessing than in nature, for by the blessing nature is changed… . Surely the word of Christ, which could make out of nothing that which did not exist, can change things already in existence into what they were not. For it is no less extraordinary to give things new natures than to change their natures… . Christ is in that Sacrament, because it is the Body of Christ; yet, it is not on that account corporeal food, but spiritual. Whence also His Apostle says of the type: `For our fathers ate spiritual food and drink spiritual drink.' [1 Cor. 10:2-4] For the body of God is a spiritual body."

-"On the Mysteries" 9, 50-52, 58; 391 A.D.:

Jerome

"After the type had been fulfilled by the Passover celebration and He had eaten the flesh of the lamb with His Apostles, He takes bread which strengthens the heart of man, and goes on to the true Sacrament of the Passover, so that just as Melchisedech, the priest of the Most High God, in prefiguring Him, made bread and wine an offering, He too makes Himself manifest in the reality of His own Body and Blood."

    -"Commentaries on the Gospel of Matthew" [4,26,26] 398 A.D.

Cyril of Alexandria

"Christ said indicating (the bread and wine): 'This is My Body,' and "This is My Blood," in order that you might not judge what you see to be a mere figure. The offerings, by the hidden power of God Almighty, are changed into Christ's Body and Blood, and by receiving these we come to share in the life-giving and sanctifying efficacy of Christ."

    -Commentary on the Gospel of Matthew 26,27, 428 A.D.:

"We have been instructed in these matters and filled with an unshakable faith, that that which seems to be bread, is not bread, though it tastes like it, but the Body of Christ, and that which seems to be wine, is not wine, though it too tastes as such, but the Blood of Christ … draw inner strength by receiving this bread as spiritual food and your soul will rejoice."

    -"Catecheses," 22, 9; "Myst." 4; d. 444 A.D.:

Augustine of Hippo

"You ought to know what you have received, what you are going to receive, and what you ought to receive daily. That Bread which you see on the altar, having been sanctified by the word of God, is the Body of Christ. The chalice, or rather, what is in that chalice, having been sanctified by the word of God, is the Blood of Christ."

    -"Sermons", [227, 21]

Marcarius the Magnesian

"[Christ] took the bread and the cup, each in a similar fashion, and said: 'This is My Body and this is My Blood.' Not a figure of His body nor a figure of His blood, as some persons of petrified mind are wont to rhapsodize, but in truth the Body and the Blood of Christ, seeing that His body is from the earth, and the bread and wine are likewise from the earth."

    -"Apocriticus" [3,23] ca. 400 A.D.

Leo I, the Great

"When the Lord says: 'Unless you shall have eaten the flesh of the Son of Man and shall have drunk His blood, you shall not have life in you,' you ought to so communicate at the Sacred Table that you have no doubt whatever of the truth of the Body and the Blood of Christ. For that which is taken in the mouth is what is believed in faith; and in do those respond, 'Amen,' who argue against that which is received."

    -"Sermons" [91,3] ante 461 A.D.

Caesarius of Arles

"As often as some infirmity overtakes a man, let him who is ill receive the Body and Blood of Christ."

    -"Sermons [13 (265), 3]

Resources

Communion in the Early Church

The Early Christians Believed in the Real Presence

What's the Difference Between Christian Denominations? (Communion)

Prayer and Fasting

Christians today agree that prayer is an important part of the Christian life, but it is often neglected or just a means to ask for what we want. In fact, it is much more, as Jesus taught us.

Similarly, fasting is often coupled with prayer, and yet many Christians don't practice fasting at all, and many churches don't teach it.

Scriptures

Matthew 4:2

“After fasting forty days and forty nights, he was hungry.”

Jesus fasted. 

Matthew 6:5-18

“And when you pray, you must not be like the hypocrites. For they love to stand and pray in the synagogues and at the street corners, that they may be seen by others. Truly, I say to you, they have received their reward. But when you pray, go into your room and shut the door and pray to your Father who is in secret. And your Father who sees in secret will reward you. 

“And when you pray, do not heap up empty phrases as the Gentiles do, for they think that they will be heard for their many words. Do not be like them, for your Father knows what you need before you ask him. Pray then like this: 

“Our Father in heaven, 

  hallowed be your name. 

Your kingdom come, 

  your will be done, 

  on earth as it is in heaven. 

Give us this day our daily bread, 

  and forgive us our debts, 

  as we also have forgiven our debtors. 

And lead us not into temptation, 

  but deliver us from evil. 

For if you forgive others their trespasses, your heavenly Father will also forgive you, but if you do not forgive others their trespasses, neither will your Father forgive your trespasses. 

“And when you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. But when you fast, anoint your head and wash your face, that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you.

Jesus taught us to pray in secret, not just publicly, to avoid grandstanding when we do pray publicly. He then gave us a clear model for prayer, to include praise, worship, thanksgiving, and supplication. Finally, Jesus said "when you fast" not "if you fast".

Mark 9:29

So He said to them, “This kind can come out by nothing but prayer and fasting.” (NKJV)

Jesus had just cast out an unclean spirit from a boy, and the disciples were asking why they hadn't been able to do so. This is how Jesus replied.

Acts 13:2-3

'While they were worshiping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them.” So after they had fasted and prayed, they placed their hands on them and sent them off.’

The disciples worshipped and fasted as a normal practice.

Acts 14:23

“Paul and Barnabas appointed elders for them in each church and, with prayer and fasting, committed them to the Lord, in whom they had put their trust.” 

The disciples prayed and fasted when appointing elders in the new churches.

Early Christian Theologians

Pope Clement I  (died 99 or 101)

“Let them, therefore, with fasting and with prayer make their adjurations, and not with the elegant and well-arranged and fitly-ordered words of learning, but as men who have received the gift of healing from God, confidently, to the glory of God. By your fastings and prayers and perpetual watching, together with your other good works, mortify the works of the flesh by the power of the Holy Spirit” 

    – Two Epistles of Virginity, 12

Tertullian (c. 160 – c. 220 AD)

“Let us fast, brethren and sisters, lest tomorrow perchance we die.” Openly let us vindicate our disciplines. Sure we are that “they who are in the flesh cannot please God;” not, of course, those who are in the substance of the flesh, but in the care, the affection, the work, the will, of it. Emaciation displeases not us; for it is not by weight that God bestows flesh, any more than He does “the Spirit by measure.” 

    – On Fasting, 17

Basil the Great, (330–379)

“Fasting gives birth to prophets and strengthens the powerful; fasting makes lawgivers wise. Fasting is a good safeguard for the soul, a steadfast companion for the body, a weapon for the valiant, and a gymnasium for athletes. Fasting repels temptations, anoints unto piety; it is the comrade of watchfulness and the artificer of chastity. In war it fights bravely, in peace it teaches stillness.” 

    – Homily on Fasting

Augustine (354–430)

“Fasting cleanses the soul, raises the mind, subjects one’s flesh to the spirit, renders the heart contrite and humble, scatters the clouds of concupiscence, quenches the fire of lust, and kindles the true light of chastity. Enter again into yourself.”

    - Sermon, On Prayer and Fasting, LXXII

Faith / Works

Do any of the orthodox branches of Christianity teach salvation by works?  That is a claim often made by protestants with regards to the Roman Catholic Church in particular. However, the Catholic Church does not, in fact, teach salvation by works. Let's look at the following decrees of the Council of Trent:

• “If anyone says that man can be justified before God by his own works, whether done by his own natural powers or by the teaching of the Law, without divine grace through Jesus Christ, let him be anathema” (Session 6; can. 1)
• “If anyone says that the sinner is justified by faith alone, meaning that nothing else is required to cooperate in order to obtain the grace of justification and that it is not in any way necessary that he be prepared and disposed by the action of his own will, let him be anathema” (Session 6: can. 9)

While those two statements seem to be in conflict, they should rightly be taken together to form an opinion on the official position taken at the time.  If we do so we can see that the RCC agrees with James that "faith without works is dead," meaning that good works are evidence of true faith, and so a true believer is one whose faith is evident in their works. The works are possible only through God's grace, not by anything we can contribute.  It is still possible that a Calvinist might say that even free will is not required, but that is another topic.

Scripture

Ephesians 2:8-9

For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, so that no one may boast.

Romans 11:6

But if it is by grace, it is no longer on the basis of works, otherwise grace is no longer grace.

Galatians 2:16

Nevertheless knowing that a man is not justified by the works of the Law but through faith in Christ Jesus, even we have believed in Christ Jesus, so that we may be justified by faith in Christ and not by the works of the Law; since by the works of the Law no flesh will be justified.

Titus 3:4-5

But when the kindness of God our Savior and His love for mankind appeared, He saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit,

James 2:14-26

What good is it, my brothers, if someone says he has faith but does not have works? Can that faith save him? If a brother or sister is poorly clothed and lacking in daily food, and one of you says to them, “Go in peace, be warmed and filled,” without giving them the things needed for the body, what good is that? So also faith by itself, if it does not have works, is dead.

But someone will say, “You have faith and I have works.” Show me your faith apart from your works, and I will show you my faith by my works. You believe that God is one; you do well. Even the demons believe—and shudder! Do you want to be shown, you foolish person, that faith apart from works is useless? Was not Abraham our father justified by works when he offered up his son Isaac on the altar? You see that faith was active along with his works, and faith was completed by his works; and the Scripture was fulfilled that says, “Abraham believed God, and it was counted to him as righteousness”—and he was called a friend of God. You see that a person is justified by works and not by faith alone. And in the same way was not also Rahab the prostitute justified by works when she received the messengers and sent them out by another way? For as the body apart from the spirit is dead, so also faith apart from works is dead.

James is not in conflict with Paul regarding justification. James is saying that true saving faith is manifested in good works. The works do not save, but the works are evidence of the faith that saves.

Early Christian Theologians

Clement of Rome (c. 35 AD – 99 AD ~ Bishop of Rome)

“Whosoever will candidly consider each particular, will recognize the greatness of the gifts which were given by him. For from him have sprung the priests and all the Levites who minister at the altar of God. From him also [was descended] our Lord Jesus Christ according to the flesh. From him [arose] kings, princes, and rulers of the race of Judah. Nor are his other tribes in small glory, inasmuch as God had promised, “Thy seed shall be as the stars of heaven.” All these, therefore, were highly honored, and made great, not for their own sake, or for their own works, or for the righteousness which they wrought, but through the operation of His will. And we, too, being called by His will in Christ Jesus, are not justified by ourselves, nor by our own wisdom, or understanding, or godliness, or works which we have wrought in holiness of heart; but by that faith through which, from the beginning, Almighty God has justified all men; to whom be glory for ever and ever. Amen. 

    ANF: Vol. I, The Apostolic Fathers, First Epistle of Clement to the Corinthians, Chapter 32.

John Chrysostom (349-407 ~ Archbishop of Alexandria)

The patriarch Abraham himself before receiving circumcision had been declared righteous on the score of faith alone: before circumcision, the text says, “Abraham believed God, and credit for it brought him to righteousness.” 

    Fathers of the Church, Vol. 82, Homilies on Genesis 18-45, 27.7

For if even before this, the circumcision was made uncircumcision, much rather was it now, since it is cast out from both periods. But after saying that “it was excluded,” he shows also, how. How then does he say it was excluded? “By what law? of works? Nay, but by the law of faith.” See he calls the faith also a law delighting to keep to the names, and so allay the seeming novelty. But what is the “law of faith?” It is, being saved by grace. Here he shows God’s power, in that He has not only saved, but has even justified, and led them to boasting, and this too without needing works, but looking for faith only. 

    NPNF1: Vol. XI, Homilies on the Epistle of Paul the Apostle to the Romans, Homily 7, vs. 27.

“For a person who had no works, to be justified by faith, was nothing unlikely. But for a person richly adorned with good deeds, not to be made just from hence, but from faith, this is the thing to cause wonder, and to set the power of faith in a strong light.”

    NPNF1: Vol. XI, Homilies on the Epistle of Paul the Apostle to the Romans, Homily 8, Rom. 4:1, 2.

“And this he removes, with great skill and prudence, turning their argument against themselves, and showing that those who relinquish the Law are not only not cursed, but blessed; and they who keep it, not only not blessed but cursed. They said that he who kept not the Law was cursed, but he proves that he who kept it was cursed, and he who kept it not, blessed. Again, they said that he who adhered to Faith alone was cursed, but he shows that he who adhered to Faith alone, is blessed. And how does he prove all this? for it is no common thing which we have promised; wherefore it is necessary to give close attention to what follows.” 

    NPNF1: Vol. XIII, Commentary on Galatians, 3:8

“For they said that the one who does not keep the law is cursed, while he shows that the one who strives to keep it is cursed and the one who does not strive to keep it is blessed. They said that he who kept not the Law was cursed, but he proves that he who kept it was cursed, and he who kept it not, blessed. Again, they said that he who adhered to Faith alone was cursed, but he shows that he who adhered to Faith alone, is blessed.” 

    Homily on Galatians 3.9-10

God’s mission was not to save people in order that they may remain barren or inert. For Scripture says that faith has saved us. Put better: Since God willed it, faith has saved us. Now in what case, tell me, does faith save without itself doing anything at all? Faith’s workings themselves are a gift of God, lest anyone should boast. What then is Paul saying? Not that God has forbidden works but that he has forbidden us to be justified by works. No one, Paul says, is justified by works, precisely in order that the grace and benevolence of God may become apparent. 

    Homily on Ephesians 4.2.9

Many more available here:
The Early Church and Justification - Compiled by Dr. C. Matthew McMahon

Creation / Age

Some denominations insist upon Young Earth Creation is the only way to properly understand the Biblical creation account and its implications on the age of the universe and that Old Earth Creation is a new view that emerged only after the 19th and 20th century scientific calculations posited ages on the order of billions of years rather than thousands of years. However, looking back to well before the modern scientific era, both Jewish and Christian theologians have recognized that the scriptures do not necessarily speak of the age of the universe but rather focuses on the fact of God as creator and the unfolding story of salvation for mankind.

In my article entitled Old Earth or Young Earth?, I included references to ancient Jewish and Christian theologians that proposed an older universe based on reading scripture long before modern scientific dating methods. Below are relevant excerpts.

St. Augustine of Hippo (354-430) noted:

"When we reflect upon the first establishment of creatures in the works of God from which he rested on the seventh day, we should not think either of those days as being like these ones governed by the sun, nor of that working as resembling the way God now works in time; but we should reflect rather upon the work from which times began, the work of making all things at once, simultaneously."

The 11th century rabbi Nachmanides (1194-1270), writing well before any modern scientific discoveries could have influenced his perspective, commented on Deuteronomy 2:7 by saying, "Why does Moses break the calendar into two parts -- 'The days of old, and the years of the many generations?' Because, 'Consider the days of old' is the Six Days of Genesis. 'The years of the many generations' is all the time from Adam forward." 

In other words, by separating the six days of creation from the genealogical timeline that starts with Adam, history is broken into two periods, which allows for flexibility in understanding the amount of time that passed prior to the creation of Adam.

Getting back to Genesis chapter 1, it is helpful to reference the Talmud to see what Jewish rabbis have said throughout history about the days of creation, since the creation account was written in Hebrew and first given to the Jews by Moses.

Here's an excerpt from an extensive article entitled Age of the Universe on the Jews for Judaism website that sheds light on how the rabbis in the Talmud have understood Genesis 1 since long before modern science uncovered evidence for an ancient universe:

The Talmud (Chagiga, ch. 2), in trying to understand the subtleties of Torah, analyzes the word "choshech." When the word "choshech" appears in Genesis 1:2, the Talmud explains that it means black fire, black energy, a kind of energy that is so powerful you can't even see it. Two verses later, in Genesis 1:4, the Talmud explains that the same word -- "choshech" -- means darkness, i.e. the absence of light.

Other words as well are not to be understood by their common definitions. For example, "mayim" typically means water. But Maimonides says that in the original statements of creation, the word "mayim" may also mean the building blocks of the universe.

Another example is Genesis 1:5, which says, "There is evening and morning, Day One." That is the first time that a day is quantified: evening and morning. Nachmanides discusses the meaning of evening and morning. Does it mean sunset and sunrise? It would certainly seem to.

But Nachmanides points out a problem with that. The text says "there was evening and morning Day One... evening and morning a second day... evening and morning a third day." Then on the fourth day, the sun is mentioned. Nachmanides says that any intelligent reader can see an obvious problem. How do we have a concept of evening and morning for the first three days if the sun is only mentioned on Day Four? There is a purpose for the sun appearing only on Day Four, so that as time goes by and people understand more about the universe, you can dig deeper into the text.

Nachmanides says the text uses the words "Vayehi Erev" -- but it doesn't mean "there was evening." He explains that the Hebrew letters Ayin, Resh, Bet -- the root of "erev" -- is chaos. Mixture, disorder. That's why evening is called "erev", because when the sun goes down, vision becomes blurry. The literal meaning is "there was disorder." The Torah's word for "morning" -- "boker" -- is the absolute opposite. When the sun rises, the world becomes "bikoret", orderly, able to be discerned. That's why the sun needn't be mentioned until Day Four. Because from erev to boker is a flow from disorder to order, from chaos to cosmos. That's something any scientist will testify never happens in an unguided system. Order never arises from disorder spontaneously and remains orderly. Order always degrades to chaos unless the environment recognizes the order and locks it in to preserve it. There must be a guide to the system. That's an unequivocal statement. The Torah wants us to be amazed by this flow, starting from a chaotic plasma and ending up with a symphony of life. Day-by-day the world progresses to higher and higher levels. Order out of disorder. It's pure thermodynamics. And it's stated in terminology of 3000 years ago.

So, there is good reason to understand "evening and morning" to mean "chaos to order" instead of "sunset to sunrise".

Further, if we are to accept that the age of the universe and the earth may be consistent with what we observe in creation (Psalm 19:1) by reading scripture as the authors intended and as the original audience would understand it, we can show how science and scripture agree, and focus on the truth of God's creative handiwork (see my article Does Evolution Explain All Life On Earth?)  instead of pointlessly arguing about the age of the earth.

Eschatology

One of the areas of greatest debate within Protestant Christianity today is eschatology (the study of "last things").  All Christians can agree that the Bible promises that God will set all things right in the end, but there are widely differing views on the specifics of what happens leading up to that.

Approaches to Eschatology

There are four major approaches taken by Biblical scholars in understanding the prophecies in Revelation and other books.

1. Historicism is an approach that sees the symbolism in Revelation as referring to people and events throughout history, similar to the prophecies of Daniel 7 that saw the coming progression of empires (interpreted as fulfilled in Babylon, Medo-Persia, Greece and Rome).
2. Preterism sees the symbolism in Revelation as paralleling the Old Testament judgement prophecies. Judgment on Israel for rejecting Jesus as the Messiah is fulfilled by the destruction of Jerusalem and the Temple in AD 70.
   (Note: There are distinct differences between partial preterism, which still looks for a future second coming of Christ, and full preterism, which sees the coming in judgment in AD 70 as the second coming of Christ and the resurrection as a spiritual resurrection in Heaven after death).
3. Futurism sees the prophecies in Revelation beginning in chapter 6 as awaiting future fulfillment.
   (Note: There are distinct differences between the Historic Futurism of the early church and the modern Dispensational Futurism, which arose in the 19th century and teaches a pretribulation rapture of the church.)
4. Idealism sees the symbolism in Revelation as allegorical or spiritual illustrations that haven't and won't necessarily ever find literal, physical fulfillment. 

Also, there are three different ways of understanding the millennium in Revelation 20.

1. Premillennialism sees the millennium as a future 1000 year reign of Jesus and the righteous on earth after the physical return of Jesus, followed by the Great White Throne judgment. This is the view held by futurists and some preterists.
2. Postmillenialism sees the millennium as a period of peace and security when the gospel has spread throughout the earth and Christ reigns in the hearts of believers worldwide. This will be followed by the physical return of Jesus for the judgment of the living and the dead. This is view is held by some preterists.
3. Amillenialism sees the millennium not as a future 1000 year reign of Jesus and the righteous on earth but rather the millenium as representing the age of the Church and the kingdom of God regining in the hearts of believers while awaiting the return of Jesus to judge the living and the dead. This view is held by most historicists, preterists  and idealists.

Historical Context 

Historic Futurism 

At the time the New Testament books were written, all Christians were naturally futurists, as the events of AD 70 had not yet transpired, nor had sufficient time elapsed for the idealist or historicist views to emerge.  The earliest documented reference is Irenaeus of Lyon (130-202 AD), who saw the fulfillment of Daniel's prophecies as future. There is also a single quote by Iraneaeus that has led many to date the writing of Revelation in the reign of Domitian (ca. 95 AD) instead of in the 60s AD as other evidence suggests. 

“We will not, however, incur the risk of pronouncing positively as to the name of Antichrist; for if it were necessary that his name should be distinctly revealed in this present time, it would have been announced by him who beheld the apocalyptic vision.

For [it or he] was seen not very long time since, but almost in our day, towards the end of Domitian’s reign.”

– Saint Irenaeus, Adversus haereses 5, 30, 3

The confusion arises by reading the ambiguous pronoun in the above quote as "it" to refer to the book instead of "he" to refer to John. 

Partial Preterism

The earliest documented reference consistent with preterist teaching is Eusebius of Caesarea (263-339 AD) who wrote the following:

When, then, we see what was of old foretold for the nations fulfilled in our day, and when the lamentation and wailing that was predicted for the Jews, and the burning of the Temple and its utter desolation, can also be seen even now to have occurred according to the prediction, surely we must also agree that the King who was prophesied, the Christ of God, has come, since the signs of His coming have been shewn in each instance I have treated to have been clearly fulfilled.

Idealism

The idealist view emerged later during the Renaissance. While the idea of nonliteral fulfillment of specific details or on a secondary level was not new, to see most or all of the book of Revelation exclusively though that lens was not consistent with the understanding of the early church. 

Historicism 

The earliest written commentary reflecting a somewhat Historicist view of Revelation was around 300 AD, by Victorinus of Pettau.  The view developed over time as some saw parallels in world events such as the barbarians descending on Rome and the rise of Islam.

From the Protestant Reformation until the late 19th century, the predominant view among Protestants was the Historicist view and an interpretation that the papacy represented the Antichrist. This view, while it still survives among some Christian groups today, faded from popularity in the mid-19th century when the most compelling interpretations would have expected to have reached the second coming, only to be disappointed. 

Dispensational Premillennial Futurism

At the same time as the decline in popularity of historicism, the newly conceived dispensationalist premillennial eschatology rose to popularity among Protestants thanks in part to the publication of the popular Scofield Reference Bible, which promoted the view in the study notes.

Which is Right?

Until Jesus returns, we won't know for certain which, of any, of the views are right, but we can apply the same approach, looking to the early church for insight.  The Idealist and Historicist views emerged late, and the modern Dispensational Futurist view was hardly considered prior to the 19th century and a unique set of circumstances.

A future return of Christ is central to the Futurist view, and the case is strong for a Preterist understanding of the Olivet Discourse (see my article This Generation), Daniel's 70 weeks (see my article Daniel's 70th Week), and the first 19 chapters of Revelation (see my article When Was Revelation Written?, 666 Number of the Beast, and Who Is The Antichrist?). Partial Preterists hold to both a future second coming of Christ and an eisegetical reading of scripture that is wholly consistent. The idealist interpretations of Revelation can also be seen as perhaps a secondary meaning provides additional insight for Christians, while the primary message is clear, that we are to overcome, for Jesus Christ reigns and will set all things right. 

As for the different understandings of Revelation 20, specifically, the answer is more speculative. Some Partial Preterists hold to the Premillenial view, which was suggested by a number of early church theologians from the second century, although the Amillennial view is more common and traces back to the third century. The Eastern Orthodox, Oriental Orthodox, and Roman Catholic churches all agree on the Amillennial interpretation, which strongly suggests it was the primary view within the historical, early church.

Conclusion

If we are to have unity in the church, we need to set aside our difference and embrace our oneness in Christ. We can recognize that there may be different views on secondary issues, while agreeing on the fundamentals of our faith. That is crucial to letting the world see Christians as committed followers of Christ, who has commanded us to be as one.

Certainly, it is also fair for study Bibles to acknowledge the various views on any topic rather than just one, and when preaching and teaching, all views should be acknowledged and examined before digging into the subject and taking the approach of the Bereans who "received the word with all eagerness, examining the Scriptures daily to see if these things were so." (Acts 17:10-12)