The term “canon” was first used to describe the doctrines which made up the essential beliefs and practices of the Christian church. Later on, and now today, the canon refers to the Scriptures that Christians regard as divinely inspired by God and contain true and right doctrine. The Greek word for canon originally meant “reed” but later morphed into “measuring reed,” eventually leading to the meaning “standard,” “norm,” or “rule.” This helps us understand that for the Christian the “canon” is the standard of faith that is found only in the Scriptures.
The primary criterion for determining canonicity is divine inspiration. This can be hard to determine however. After all, many other religions began on what men said were “inspirations” from God. Therefore, there are three filters that church leaders used to determine whether or not a document was divinely inspired.
- Rule of Faith. If a document was not consistent with orthodoxy, it would not be considered a part of the canon. In other words, the document must contain “Christian truth recognized as normative in the churches.”
- Apostolicity. A document must have been authored by an apostle or one who had immediate contact with the apostles (i.e. Luke with Paul and Mark with Peter).
- Acceptance by Churches Everywhere. This criterion was not the most significant, but it was still used by early Christians. If a document had wide acceptance across geographical spectrums, it was more likely to be considered part of the canon.
The “Rule of Faith” and apostolicity appear to be the two most important criteria for recognizing whether or not a document was canonical. The rule of faith is obvious enough: if a document blatantly rejected an orthodox teaching or includes traditions of man, then it would have been canonical. Furthermore, if a document did not edify the church by pointing them to the person and work of Christ and spurring them on toward righteous living, then it would not be canonical.
Apostolicity is important because the apostles (and by direct relationship Luke and Mark) spoke the words of God as the prophets of old did. Hebrews 1:1 -2 (ESV) says, “Long ago, at many times and in many ways, God spoke to our fathers by the prophets, but in these last days he has spoken to us by his Son.” God ordained that the New Covenant would be ushered in by and centered upon Jesus. He also ordained that this New Covenant (or “Testament”) be written down and proclaimed by apostles (literally “messengers”) who would reveal God’s plan of redemption ultimately fulfilled in Jesus Christ.
Chronology of Development
The key for us in thinking about the development of the canon is that the job of early Christians was not to “establish” a canon, as if they created the Bible. Rather, their duty was to “recognize” what God had already designated as Scripture. Recognizing the canon was helped by early church fathers who included quotes from Scripture in their writings. Among the most significant are Augustine, Athanasius, Clement, Origen, and Eusebius.
The Canon of Marcion, released in A.D. 140, “contained only a mutilated Gospel of Luke and ten of Paul’s epistles (excluding the Pastorals).” Carson and Moo write that Marcion’s work, along with other heretics, “spurred the church to publish more comprehensive and less idiosyncratic lists” of canonical books. The first list that included all twenty-seven books of our current New Testament was the Easter Letter by Athanasius in A.D. 367. The Third Council of Carthage in A.D. 397 recognized all twenty-seven books, and from that time the Western church has had little debate about the canon.
It is interesting to note that 2 Peter 3:16 refers to Paul’s epistles as “Scripture.” Paul, in 2 Timothy 3:16, wrote that all Scripture is “breathed out by God,” and so Peter, in his epistle, recognized that Paul was writing the words of God. Paul also quotes Jesus (in Matthew 10:10) alongside the Old Testament and refers to both as “Scripture.” These passages, among others, served as road signs for the early Christians to navigate toward God’s divinely inspired texts.
Should the Canon Stay Closed?
If someone suggested that the biblical canon should re-open, how would you answer? God has fully revealed himself and his will in the person of Jesus Christ (see Heb. 1:1-4 and brief discussion above) and so God’s revelation cannot be added to or subtracted from. Lea and Black write, “The New Testament canon contains the authoritative record of Jesus’ life and the interpretation of its significance.” Furthermore, because God is a “self-disclosing, speaking, covenant-keeping God who has supremely revealed himself” in Jesus, we must hold fast to keeping the canon closed for the glory of God and the spread of the canon’s message: the gospel of Jesus Christ.
 Thomas D. Lea and David Alan Black, The New Testament: Its Background and Message, p. 70.
 For a brief note on the origin of the word “inspiration,” see footnote #28 in D.A. Carson and Douglas J. Moo, An Introduction to the New Testament, p. 737.
 Ibid., p. 726.
 Lea and Black, p. 71.
 Carson and Moo, p. 736.
 Ibid., p. 742.
 Lea and Black, p. 73.
 Carson and Moo, p. 732.
 Ibid., p. 734.
 Ibid., p. 735.
 Lea and Black, p. 74-75.