At some time in the Christian historical narrative, twenty-seven books of the New Testament became the chosen texts to convey the accepted teachings of Jesus and the Apostles. The literature about early Christianity suggests that many of these texts were already in use by the early orthodox fathers. They gave weight to both oral and written revelation and proclamation. The Gnostics used many of the same texts; however, they interpreted the scriptures in different ways, according to their “fuller” understanding of Jesus' teachings within the Gnostic tradition. It seems that Jesus, in his references in the Old Testament to the many Hebrew scriptures, signaled his acceptance of the texts and their usage. But he had already died before the writings of the New Testament took place. So when and how was the canon established and by whose authority? Can it ever be changed? These are questions that some theologians and biblical historians still consider worth discussing.

After the Apostolic Age, no decisive list of sacred texts that constituted a canon for the orthodoxy existed — or if it did, it did not survive. As mentioned in a previous chapter, the Gnostic Marcion in the second century gathered together sacred texts into his version of a canon that included the Gospel of Luke, which he edited, and ten of Paul's letters (excluding the first and second pastoral Epistles of Timothy and Titus, plus the letter to the Hebrews). Marcion excluded any texts with which he disagreed. In their rejection of Marcion and his Gnostic theology, the early church fathers were forced to think about their own beliefs and to clarify them for their Christian churches and communities. Paramount among their concerns were the sacred texts that were circulating (which ones were acceptable and which ones weren't), the relationship between the Jewish Christians and the Gentile Christians, and heretics and their heresies, as well as reliability of sources (texts versus inspired dialogues, visions, etc.) for information about Jesus.

The Muratorian Canon was a list of sacred texts compiled, possibly in Rome, by an unknown individual just before the end of the second century, although some argue that the Muratorian Canon is actually a fourth-century list. The canon bears the name of L. A. Muratori, the Italian scholar who discovered the canon. Found in the eighteenth century in a library in Milan, the document includes all of the books of the New Testament as being canonical with the exception of Hebrews, James, and the second book of Peter. The Apocalypse of Peter, a Gnostic text, was included but later was rejected.

Not until the fourth century did the term “canon” come into usage as a religious term to refer to the sacred texts of both the Hebrew scriptures (Old Testament) and the New Testament. By then, the early church fathers perceived a need for an authoritative corpus of writings to support the church's religious rules on issues relating to faith and practice.

By the latter half of the century, after John, the last Apostle, had died, the Christian fathers recognized the importance of two groups of documents: Paul's letters and the Gospels of Matthew, Mark, Luke, and John. These items must have carried great significance as authoritative texts. But the four gospels could be said to be for a Jewish audience (especially Matthew) while the Pauline letters targeted the Gentile communities of Christians. It was the Acts of the Apostles, the second of Luke's two-volume work, that bridged these the four gospel accounts with Paul's letters. Luke stressed in Acts that Christianity, like Judaism, deserved Rome's fair treatment and tolerance. The following is a timeline for the New Testament.

Approximate Composition Dates of New Testament Texts