Were the books of the New Testament selected by Emperor Constantine for social and political reasons in the 4th century (cf. the claims of Dan Brown via The Da Vinci Code) or were the books included in the New Testament Canon because they fit with the authoritative teaching that can be traced back to Jesus himself? Was this simply a power play? Another example of history being written by the winners?
I think the best way to come at this is by asking which of these documents tells us the truth about ‘the faith’ that was preached and received in the earliest communities of Christ-followers (cf. Jude 3). This is a theological question—what did the earliest eyewitnesses of the life and ministry of Jesus of Nazareth believe and preach from the very beginning?
New Testament scholar Darrell Bock points to three kinds of texts contained in the New Testament writings that show us what the earliest Christians believed (and helpfully provides 3′s).
Schooling—We find doctrinal summaries Christians would memorize and read alongside Old Testament texts (i.e., the Hebrew Scriptures) when they would gather together for worship in house churches (e.g., Rom. 1:2-4; 1 Cor. 8:6; 15:1-5).
Singing—they would sing their theology in hymns and show their devotion to the Lord Jesus Christ (e.g., Col. 1:15-20 & Phil. 2:5-11).
Sacraments—Baptisms and the Lord’s Supper were practiced on a regular basis and pictured (imaged or symbolized) for the believing community the basic elements of the salvation story as core theology (e.g., Matt. 28:19-20; 1 Cor. 11:23-26; Eph. 4:4-6).
These creeds, hymns, and practices predated the writing of the New Testament documents (remember that this was an oral culture and many people could not read). Think of these as “oral texts” the earliest Christian community read and practiced before there was a completed Bible. These foundational beliefs are sometimes called the “Rule of Faith.”
With that in mind, how were the books chosen? There were three criteria used to decide which books were received as authoritative—as canon.
First, was a book written by an apostle or an associate of an apostle (apostolicity)? Mark was accepted because he was an associate of Peter and Luke was accepted because of his relationship to Paul. Or to put it another way, if the book was not from the 1st century it was not Scripture because it could not be traced back to the apostles who were taught and commissioned by Jesus (who was crucified in A.D. 30-33).
Secondly, did this book conform to the teachings / theology of other books known by the apostles (orthodoxy)? Recall the points made about the schooling, singing, and sacraments in the life and worship of the early church. Hebrews would be an example of this because of its exalted view of Jesus Christ (i.e., Christology).
Finally, was the book accepted early on in the life of the church and by the majority of churches across the region (catholicity)? It was important that a book wasn’t just accepted in one location, but that lots of Christians in different cities and regions accepted it.
Early Christians recognized the authority contained in these writings already; they did not arbitrarily pick which ones would become authoritative for the Church. The early Christians were very careful and thoughtful about which books would get the label ‘Scripture’ alongside the Old Testament. It is simply a fact of history that by the end of the 2nd century (before Constantine), the four Gospels, Acts, and the letters of Paul are already recognized as authoritative and being used that way in house churches. Now some discussion about a handful of books continued on through the centuries between the Eastern and Western churches. But, while there was no universal declaration concerning the final list, it is safe to say that the canon was effectively closed by the time of the Council of Carthage in 397 A.D.
*A form of this article first appeared in a contribution I made to the Apologetics Study Bible for Students, published by B&H.