Why does the New Testament contain these twenty-seven books, and not others? A popular story says that the emperor Constantine, or the Council of Nicaea in 325, chose the books and suppressed the rest. That story, made famous by novels, is not true: the Council of Nicaea did not discuss the canon at all. The real history is longer, more gradual, and in many ways more interesting.

Scripture before the New Testament

The first Christians already had a Bible: the Jewish scriptures, which they read as pointing to Christ. When the New Testament writers speak of “Scripture,” they mean what we call the Old Testament.

But from the beginning, the words of Jesus carried an authority equal to scripture. Paul can settle a question by quoting “the Lord” (1 Corinthians 7:10; 11:23), and he expected his own letters to be read in the churches and obeyed (1 Thessalonians 5:27; 2 Thessalonians 3:14). Within the New Testament itself, 2 Peter 3:15–16 places “all of his letters,” Paul’s, alongside “the other Scriptures,” and 1 Timothy 5:18 quotes a saying found in Luke 10:7 next to a verse of Deuteronomy, introducing both with “the Scripture says.”

So the idea of new, authoritative Christian writings is as old as the writings themselves. The question was which writings belonged.

The second century: Gospels and Paul

By the middle of the second century, the core of the New Testament was in wide use.

The Gospels. Around 150 CE, Justin Martyr describes Christian worship in Rome: on Sunday, “the memoirs of the apostles or the writings of the prophets are read, as long as time permits” (First Apology 67). He calls these memoirs “Gospels.” Justin’s pupil Tatian, around 170 CE, made the Diatessaron (“through four”), a single continuous narrative woven from Matthew, Mark, Luke and John, which shows that these four were already a recognised set. Around 180 CE, Irenaeus of Lyons argued that there can be neither more nor fewer than four Gospels, comparing them to the four winds and the four corners of the world (Against Heresies 3.11.8). His argument is unusual, but his assumption is clear: the four Gospels were the Gospels of the church. Charles Hill, in Who Chose the Gospels?, shows that this fourfold Gospel was established earlier and more widely than is often assumed.

Paul. Paul’s letters were collected early (see How the New Testament was written). Early second-century writers such as Clement of Rome, Ignatius of Antioch and Polycarp of Smyrna know and echo several of them. The papyrus codex P46, from around 200 CE, is a collection of Paul’s letters that includes Hebrews.

Marcion and the challenge of a short canon

Around 140 CE, a wealthy shipowner from Pontus named Marcion came to Rome and taught that the God of the Old Testament was a different, lesser God from the Father of Jesus. He rejected the Jewish scriptures entirely and accepted only an edited form of Luke’s Gospel and ten letters of Paul, removing passages that contradicted his views.

Marcion is sometimes said to have created the idea of a New Testament canon, forcing the church to respond with its own. Most scholars now think that overstates his influence: the church was already reading the Gospels and Paul as authoritative. But Marcion’s challenge did push Christian teachers to state more clearly which books were accepted and why. Irenaeus and Tertullian wrote at length against him.

The edges of the collection

While the Gospels, Acts and Paul’s letters were widely accepted by the late second century, some other books were treated differently in different places.

  • Hebrews was accepted early in the East, often as Paul’s, but questioned in the West, where its authorship was doubted.
  • Revelation was widely accepted in the West, but questioned in parts of the East, partly because of debates about its teaching on the end of the age.
  • Some of the shorter general letters, James, 2 Peter, 2 and 3 John and Jude, were less widely known or used, and some writers expressed doubts about them.
  • On the other side, some churches read books that were eventually not included, such as the Shepherd of Hermas, the Letter of Barnabas, 1 Clement and the Didache. Codex Sinaiticus, from the fourth century, includes Barnabas and Hermas after Revelation.

A document called the Muratorian Fragment, a Latin list of New Testament books, illustrates this. It accepts the four Gospels, Acts, thirteen letters of Paul, Jude, two letters of John and Revelation, along with the Wisdom of Solomon; it mentions the Apocalypse of Peter as disputed; and it says that the Shepherd of Hermas may be read but not publicly in church, because it was written recently. Most scholars date it to the late second century, though some, following Albert Sundberg and Geoffrey Hahneman, argue for the fourth.

Origen and Eusebius

In the third century, Origen of Alexandria, who travelled widely and knew the practice of many churches, distinguished between books accepted everywhere and books disputed in some places.

In the early fourth century, the historian Eusebius of Caesarea made a similar survey (Church History 3.25). He sorted books into:

  • the recognised books (the four Gospels, Acts, Paul’s letters including Hebrews, 1 John, 1 Peter and, with hesitation, Revelation);
  • the disputed books, “which are nevertheless known to most” (James, Jude, 2 Peter, 2 and 3 John);
  • the spurious books, which some churches read but which were not accepted (such as Hermas and Barnabas);
  • and books put forward by heretics under apostles’ names, such as the Gospel of Peter and the Gospel of Thomas, which he rejects outright as absurd and impious.

Eusebius’s survey shows that the church’s canon grew mainly by consensus, and that by his time the disputed books were few and small.

Athanasius and the councils

In 367 CE, Athanasius, bishop of Alexandria, sent his annual Easter letter to the churches of Egypt. In his thirty-ninth Festal Letter, he listed the books of the Old and New Testaments. His New Testament list is exactly the twenty-seven books we have today. “These are the springs of salvation,” he wrote, and “let no one add to them, or take anything from them.” He added that other books, such as the Didache and the Shepherd, could be read by new believers for instruction, but were not part of the canon.

In the West, regional councils at Hippo (393) and Carthage (397 and 419), in which Augustine took part, listed the same twenty-seven books. Pope Innocent I gave a similar list in 405. In the East, some churches were slower to accept Revelation, and the Syriac church for a long time used a shorter canon. But from the late fourth century onwards, the twenty-seven books were the New Testament of the great majority of Christians, and they remain so in Catholic, Orthodox and Protestant churches today.

It is worth noticing what the councils did. They did not create the canon; they recognised and confirmed books that the churches had been reading, in most cases, for two centuries or more.

How did the church decide?

Early Christian writers mention several considerations, which scholars often summarise as three questions:

  • Apostolic origin. Was the book written by an apostle, or by someone closely connected with the apostles, such as Mark (with Peter) or Luke (with Paul)?
  • Agreement with the faith. Does it agree with the “rule of faith,” the core teaching handed down in the churches from the apostles?
  • Wide and long use. Has it been read and valued in churches across the Christian world from early times?

Michael Kruger argues that alongside these, Christians believed that the books of the canon carried their own authority: that the church recognised in them the voice of its Lord, rather than conferring authority on them. Lee Martin McDonald emphasises the human, historical process by which communities reached agreement. Both perspectives describe real aspects of the history.

What about the other gospels?

Books such as the Gospel of Thomas, the Gospel of Peter or the Gospel of Judas are sometimes presented as “lost gospels” that were unfairly excluded. In fact, they were known in the early church, discussed, and generally rejected because they were later than the four Gospels, not connected with the apostles in any reliable way, or taught a different message. Most scholars date them to the second century or later. They are valuable for understanding the variety of early Christianity, but there is no evidence that any of them was ever widely read alongside the four Gospels as scripture.

Sources

  • Athanasius. Festal Letter 39 (367 CE).
  • Bruce, F. F. The Canon of Scripture. Downers Grove, IL: InterVarsity, 1988.
  • Eusebius. Church History 3.25; 6.25.
  • Gallagher, Edmon L., and John D. Meade. The Biblical Canon Lists from Early Christianity: Texts and Analysis. Oxford: Oxford University Press, 2017.
  • Hahneman, Geoffrey Mark. The Muratorian Fragment and the Development of the Canon. Oxford: Clarendon, 1992.
  • Hill, Charles E. Who Chose the Gospels? Probing the Great Gospel Conspiracy. Oxford: Oxford University Press, 2010.
  • Irenaeus. Against Heresies 3.11.8.
  • Justin Martyr. First Apology 67.
  • Kruger, Michael J. Canon Revisited: Establishing the Origins and Authority of the New Testament Books. Wheaton, IL: Crossway, 2012.
  • McDonald, Lee Martin. The Biblical Canon: Its Origin, Transmission, and Authority. Peabody, MA: Hendrickson, 2007.
  • Metzger, Bruce M. The Canon of the New Testament: Its Origin, Development, and Significance. Oxford: Clarendon, 1987.
  • Bible quotations are from the World English Bible (public domain), except where the article gives its own literal rendering.