Here’s a short article by Timothy W. Massaro entitled “6 Things We Need to Know about the Formation of the Bible” – original source these councils affirmed the books they believed had functioned as foundational documents for the Christian faith. The councils merely declared the way things had been since the time of the apostles. Thus, these councils did not create, authorize, or determine the canon. They simply were part of the process of recognizing a canon that already existed.
2. Early Christians believed that canonical books were self-authenticating.
Another authenticating factor was the internal qualities of each book. These books established themselves within the church through their internal qualities and uniqueness as depicting Christ and his saving work. The New Testament canon we possess is not due to the collusions of church leaders or the political authority of Constantine, but to the unique voice and tone possessed by these writings.
3. The New Testament books are the principle Christian writings we have.
The New Testament books are the earliest writings we possess regarding Jesus. The New Testament was completed in the first century. This means the writings include testimonies from eyewitnesses and were written within fifty years of the events, which cannot be said of any of the apocryphal literature often discussed in the news. This is particularly evident when it comes to the four gospels. Matthew, Mark, Luke, and John are the only gospel accounts that originate in the first century.
4. The New Testament books directly relate to the apostolic testimony.
Unlike any book from that period or the following century, the New Testament books were directly connected to the apostles and their testimony of the resurrected Christ. The canon is intimately connected to their activities and influence. The apostles had the very authority of Christ himself (Matt. 28:18–20). Along with the Old Testament, their teachings were the very foundation of the church. The church is “built on the foundation of the apostles and the prophets” (Eph. 2:20).
5. Some New Testament writers quote other New Testament writers as Scripture.
The belief in new revelation or a testament of books was not a late development. From the days of the apostles themselves, these writings were seen as unique in their authority and witness. This belief seems to be present in the earliest stages of Christianity. In 2 Peter 3:15–16, Peter refers to Paul’s letters as “Scripture,” which would have put them on a par with the books of the Old Testament. This is a significant fact that is often overlooked.
6. Early Christians used non-canonical writings without analogous authority.
Christians often cited non-canonical literature with positive affirmation for edification. Yet, Christians were simply using these books as helpful, illuminating, or edifying texts. Rarely was there confusion as to whether they were on a par with Scripture. These books were eventually disregarded according to the criteria of whether they had general acceptance, apostolicity, and self-authentication.