Thanks to Dan Brown’s novel, The Da Vinci Code, and its film adaptation, many people think that the books that constitute today’s New Testament (NT) were first chosen in the 4th century at the Council of Nicaea. However, early in the 2nd century, Church Fathers had already identified the majority of the books contained in the NT canon as holy scripture and the idea that a handful of bishops and the Roman Emperor Constantine the Great created that canon is a myth.
What Is a Canon?

The word “canon” comes from the Latin “kanon,” which literally means “measuring rod.” With regard to the New Testament, it refers to the books that the Christian Church sees as divinely inspired. As such, they are authoritative and represent the standard by which all things are measured for Christ’s followers. Being a bookish bunch, the Church Fathers held the written word in high regard, and the Gospels of Matthew, Mark, Luke, and John, as well as the Apostle Paul’s letters and numerous other texts made the rounds of congregations throughout the Mediterranean world.
Council of Nicaea

From May to the end of July in 325 CE, some 300 bishops from churches throughout the Roman Empire met in the city of Nicaea (now Iznik, Turkey) at the request of Constantine the Great. At that time, the Church was dealing with Arius, a presbyter in the city of Alexandria, who preached that Jesus was not eternal and not divine but was a mere creation of God. Because of discord over this issue, Constantine convened the council, hoping that it could be resolved. Whether Constantine did this because of Christian beliefs or because he wanted to eliminate any unrest in his bailiwick is debatable.
Ultimately, the Council produced the Nicene Creed, which outlines the Bible-based belief that God exists as a Trinity of God the Father, God the Son, and God the Spirit. However, it contained no information about the books of the canon.
Source of the Nicaea Council Myth

Erroneous beliefs about the council started with the discovery of a 9th-century Greek manuscript called the Synodicon Vetus, which offered a summary of decisions made by a variety of councils, including that of Nicaea. Edited by John Pappus, it was published in 1601 in Strasbourg, France. The text purports that the Council attendees placed a number of books on a table, praying that the Lord would tell them which were divine by placing the spurious ones underneath. According to the Synodicon Vetus, “it so happened.”
Proving to be popular with the public, Pappus’s publication circulated widely. Eventually, it made its way to 18th-century French philosopher and satirist, Voltaire, an outspoken critic of Christianity. He recorded in his Philosophical Dictionary that the books of the New Testament were chosen “by prayer and a miracle.” There is, however, no evidence to support that claim.
Self-Authentification and Apostolicity

The Early Church Fathers did not see themselves as choosing what books should be scripture, but rather, they believed that the Holy Spirit revealed to them what writings were “of God” and which were not. They also believed that only those who were filled with the Holy Spirit would be able to grasp their divine source.
Theophilus, Bishop of Antioch from 185 to 191, stated that “the holy writings teach us, and all the spirit-bearing men . . . .” (Autol. 2.22, ANF). Clement of Rome asserted that Paul’s first letter to the Corinthians was written “with true inspiration” (1 Clem. 47.3). This understanding of the revelation of scripture came to be called the “internal testimony” of the Holy Spirit. As far as the early Church Fathers were concerned, scripture identified and authenticated itself. Their job was merely to recognize it and respond accordingly.
For acceptance into the canon, books had to be written by someone who, as an apostle, knew Jesus personally or by people who knew an apostle who had been a witness to his life. This is why the so-called “lost gospels” are not part of the New Testament. For example, the Gospel of Thomas, while bearing the name of a disciple, was not written until approximately 140, long after Thomas was gone. The same is true of the Gospel of Philip, the Gospel of Mary, the Gospel of Judas, and the Gospel of Barnabas, among others. Such books bear the label “pseudepigrapha,” which literally means false writing.
General Acceptance and Orthodoxy

Books had to be in wide use and accepted as scripture by a majority of Christians. There was a practicality to their acceptance of books. If they were useful, churches included them. However, there were some popular texts such as the Didache (a code of conduct teaching Christians how to live) and The Shepherd of Hermas (a text on ethics) that were widely used, but they did not fit the criterion of apostolicity and were written in the 2nd century. Therefore, they were excluded from the New Testament Canon.
The New Testament books preach and teach the same message about the Triune Godhead with Christ coming to Earth as God Incarnate who died on our behalf for our sins, his resurrection being a defeat of death, with salvation given to all who want to receive it. Books that presented anything contrary to basic Christian doctrine were not included in the canon. Again, this explains why pseudepigraphical writings are not in the NT. They contradict the teachings of orthodox Christianity. For example, Serapion, patriarch of Antioch from 191 to 211, decreed that the Gospel of Peter should not be read in church. He called it a forgery, given that it was written well into the 2nd century and could not have been written by Peter. Additionally, it was a heretical Gnostic text, denying the Trinity and the death and the bodily resurrection of Christ. Therefore, it did not line up with Christian doctrine as presented in the Gospels and the other books considered scripture.
Marcion and the Earliest Canon

Marcion was born in 85 CE in Sinope, a town on the Black Sea, in what is now known as Turkey. He joined the Christian church in Rome between 135 and 139. He was not a part of it for long, however, as he was excommunicated in 144 for his heretical views about God. He insisted that the God of the Old Testament, whom he saw as angry and vengeful, was not the father of a loving Jesus Christ. He chose 13 letters by Paul and his own highly-edited version of the Gospel of Luke for his list of scripture. Scholars believe it to be the first canon compiled.
However, the Church rejected it. Marcion’s misguided theology spurred the early Church Fathers to think seriously about which books were inspired by God and which were not. Tertullian (born around 145), a presbyter in Carthage (North Africa), was one such Father. He wrote Five Books Against Marcion, in which he defended the texts that the heretic left out, including the Gospels of Matthew, Mark, and John. Ultimately, these discussions led to the formation of another canon, namely the Muratorian Fragment.
The Muratorian Fragment

Ludivico Antonio Muratori found a list of New Testament books in the Ambrosian Library in Milan, which he published in 1740. Hence, it bears his name. Because the beginning of it is lost, it is referred to as a fragment. There is no way to determine who wrote it. However, it has been dated to the late second half of the second century because its author refers to the episcopate of Pius I of Rome, who died sometime between 154 and 157 CE. The list includes Luke and John, the Acts of the Apostles, the Pauline Epistles (13), two letters of John, Jude, the Wisdom of Solomon, the Apocalypses of John and Peter, and the Shepherd of Hermas.
One might ask why the Wisdom of Solomon was included in this list since it clearly belongs to the Old Testament. Additionally, Peter and John’s Apocalypses did not end up as part of the New Testament canon. Nor did the Shepherd of Hermas. So why are they noted? Scholars speculate that the authors of such lists often included books that were considered useful but not divine in origin at the very end of them. Therefore, the author was naming books that were not considered to be inspired by God but still had some value for the Church.
The Earliest References From the Earliest Church Fathers

An understanding of what books the Church deemed scripture does not depend solely on lists. The early Church Fathers quoted and wrote about the books of the New Testament extensively, and it is from them that we learn how the various books in circulation were regarded.
The earliest evidence regarding canonical texts comes from Papias (born approximately 60 CE), who was bishop of Hierpolis in Phrygia in what is now the country of Turkey. He noted that Mark wrote his gospel from information Jesus’s disciple, Peter, shared with him. He also mentioned Matthew, John, and 1 Corinthians, so we know that those books were already starting to circulate widely amongst the churches. He wrote a five-volume book, but we only have a small part of it. Who knows what other NT books he might have mentioned in the material that is lost to us?
Polycarp, a contemporary of Papias, was born around 69 CE in the city of Smyrna, also in what is now Turkey. He was a disciple of John, who was, in turn, a disciple of Jesus. In a letter to the Philippians, written in 115, Polycarp quoted or alluded to no less than 20 of the books that are in the New Testament. Ignatius (circa 35 to 107) wrote letters shortly before Polycarp’s letter to the church at Philippi in which he named 17 of the books, while Clement of Rome, born around 35 CE, wrote an epistle around 96 CE that included references to 14 of the books. So there is early attestation of the importance of the texts included in the modern New Testament.
Later Church Fathers

2nd-century Church Fathers continued to write about and include books that ended up in the official canon of the New Testament. Irenaeus was one such figure.
Born anywhere from 120 to 140 somewhere in Asia Minor, Irenaeus founded a church in Gaul (modern France) in the city of Lyon. His contribution to a discussion of the NT canon largely rests on his insistence that there were four, and only four, gospels, that is, Matthew, Mark, Luke, and John.
He wrote, “It is not possible that the Gospels can be either more or fewer in number than they are. For, since there are four zones of the world in which we live, and four principal winds, while the Church is scattered throughout all the world, and the pillar and ground (1 Tim. 3:15) of the Church is the Gospel and the spirit of life; it is fitting that she should have four pillars, breathing out immortality on every side, and vivifying men afresh” (Against Heresies, 3.11.8.).
Clement of Alexandria

Titus Flavius Clemens, known as Clement, was born around 150, possibly in Athens. After traveling around the Mediterranean for several years and studying with a variety of teachers, he landed in the Egyptian city of Alexandria. He advanced from student to headmaster of the so-called Alexandrian school and remained in that city for 22 years. He was a prolific writer who quoted from most of the books that are now in the New Testament canon. In fact, he makes some 3,200 references to NT writings. The only books he did not clearly quote were Philemon, James, 2 Peter, and 3 John.
Interestingly, he quoted from the Pauline epistles word for word as if he had the text for them in front of him, but quoted the gospels loosely. Scholars believe this is because he was so familiar with Matthew, Mark, Luke, and John that he had their contents memorized and, as a result, did not quote them verbatim.
Origen

Origen, who was born around 185, studied under the tutelage of Clement of Alexandria. With a penchant for writing allegories, he offered a list of canonical books in his story of Joshua, dated around 250. He wrote,
“But when our Lord Jesus Christ comes, whose arrival that prior son of Nun designated, he sends priests, his apostles, bearing ‘trumpets hammered thin,’ the magnificent and heavenly instruction of proclamation. Matthew first sounded the priestly trumpet in his Gospel; Mark also; Luke and John each played their own priestly trumpets. Even Peter cries out with trumpets in two of his epistles; also James and Jude. In addition, John also sounds the trumpet through his epistles [and Revelation], and Luke, as he describes the Acts of the Apostles. And now that last one comes, the one who said, ‘I think God displays us apostles last,’ and in fourteen of his epistles, thundering with trumpets, he casts down the walls of Jericho and all the devices of idolatry and dogmas of philosophers, all the way to the foundations” (Hom. Jos. 7.1).

In another work, Origen listed all of the authors of the books of the New Testament in his Homilies on Genesis. He wrote, “Isaac, therefore, digs also new wells, nay rather Isaac’s servants dig them. Isaac’s servants are Matthew, Mark, Luke, John; his servants are Peter, James, Jude; the apostle Paul is his servant. These all dig the wells of the New Testament” (Hom. Gen. 13.2).
Some scholars dispute the use of these passages canonically, suggesting that Rufinus of Aquileia tampered with the material when he translated Origen’s work into Latin around 400, making it reflect the accepted list of books cited by Athanasius (see below) earlier in the 4th century as well as his own ideas of what belonged in the canon. However, there is a paucity of evidence to support that theory, and many scholars argue for the reliability of Rufinus as a translator.
Athanasius

Athanasius was born in the Egyptian city of Alexandria in the 290s. Athanasius attended the Council of Nicaea as secretary to Alexander, the Bishop of Alexandria. He became a powerful defender of the Trinity (one God in three persons, God the Father, God the Son, and God the Holy Spirit). He became the bishop of Alexandria three years after the council was held. Traditionally, the bishops of Alexandria would send out a festal letter citing the date when Easter would be celebrated to all those within his purview.

In 367, Athanasius’s letter included a list of the New Testament canon. It represents the first list of the books in the NT in its final form. He wrote:
“Continuing, I must without hesitation mention the scriptures of the New Testament; they are the following: the four Gospels according to Matthew, Mark, Luke, and John, after them the Acts of the Apostles and the seven so-called catholic epistles of the apostles — namely, one of James, two of Peter, then three of John and after these one of Jude. In addition there are fourteen epistles of the apostle Paul written in the following order: the first to the Romans, then two to the Corinthians and then after these the one to the Galatians, following it the one to the Ephesians, thereafter the one to the Philippians and the one to the Colossians and two to the Thessalonians and the epistle to the Hebrews and then immediately two to Timothy, one to Titus and lastly the one to Philemon. Yet further the Revelation of John.”
Athanasius went on to say that “these are the springs of salvation, in order that he who is thirsty may fully refresh himself with the words contained in them. In them alone is the doctrine of piety proclaimed. Let no one add anything to them or take anything away from them . . .”
Many took this to mean that the canon was officially closed.
Disputed Texts

While the Church accepted most of the books in the NT without much argument, there were some that were disputed, including the Letter to the Hebrews. While some attributed its writing to the Apostle Paul, others insisted that the writer was unknown. Given the possibility of its anonymity, it did not fit the criterion of apostolicity. However, its contents lined up with basic Christian doctrine, and many theologians considered it inspired. Therefore, it was, in the end, included.
Some Church Fathers rejected 2 Peter because its style is so different from 1 Peter. However, it could be that Peter dictated his letter to an amanuensis (secretary) who put down the apostle’s words in his own manner.
Some questioned Jude because it included a saying from the Book of Enoch, a book not included in the Old Testament. So the book barely squeaked into the New Testament.
Even as late as the 16th century, theologians questioned the inclusion of James. Martin Luther thought that its statement that “faith without works is dead” (2:26) would mislead people into believing that a person had to earn his or her way into Heaven by doing good works. This contradicted the understanding that salvation is by faith and faith alone as stated in Eph. 2:4. Additionally, while some thought James, the brother of Jesus, wrote it, others believed it to be anonymous. Yet, again, it was ultimately included because it was considered to be divinely inspired.

The second and third letters of John made it into the canon despite questions about their authorship. No one doubted that John wrote the first letter, but there was no evidence beyond tradition that made him the author of the second.
The Book of Revelation represents the most hotly contested text in the New Testament. It differed considerably from John’s other work, and some believed that its bizarre contents could easily be misunderstood and misconstrued. But some Church Fathers, such as Justin Martyr (roughly 100 to 165), backed its inclusion. Martyr wrote,
“And further, there was a certain man with us, whose name was John, one of the apostles of Christ, who prophesied, by a revelation that was made to him, that those who believed in our Christ would dwell a thousand years in Jerusalem; and that thereafter the general, and, in short, the eternal resurrection and judgment of all men would likewise take place” (Justin Martyr, Dialogue 81.4).
And so Revelation is part of our New Testament today, but people still hotly debate the meaning of its contents just as some of its critics predicted centuries ago.