How Do We Know Which Books Belong in the New Testament?
Five crucial characteristics mark all writings included in the New Testament and no writings that have been left out. These are the five “criteria of canonicity.”
Read time: 4 min
Christian scholars typically point to five “criteria of canonicity”—qualities that mark writings that can and should be trusted as divinely inspired, inerrant, and belonging in the New Testament canon. Remember: κανών = kanōn = canon (Gal 6:16), which means “the rule or standard.” This is a common term Christians use to refer to the authoritative collection of writings of the Old and New Testaments. In this Q&A, we’re talking about the New Testament.
The Five Criteria
1. Apostolicity
The apostolicity of a writing means that it carries unadulterated apostolic authority. There are only two ways that a book could carry such authority: either it was written directly by an apostle of Christ (e.g. the Gospel of Matthew by Matthew, the Epistle to the Galatians by Paul, etc.) or it was written by an intimate associate of an apostle, and thereby is truly representative of the apostolic message, their experiences, and God’s truth (e.g. Mark, written by John Mark, a close associate of Peter; Luke and Acts, written by Luke the Physician, a traveling companion of the apostle Paul). Apostolicity is the foundational criterion for a canonical book. The other four criteria aid in establishing this basic criterion. A book that meets the criteria of apostolicity is not made authoritative by an ecclesiastical edict but is merely recognized officially as being so.
2. Antiquity
The antiquity of a writing refers to its age; specifically that it is manifestly ancient enough to have been apostolic. A book written in the 2nd century, for example, would be too young (written too late) to have been the work of an apostle or his close associate. Although a book being written in the first century, during the time of the apostles, does not alone qualify it for canonization, the antiquity criterion does automatically rule out any book that is not a first century work.
3. Orthodoxy
The criterion of orthodoxy relates to the agreement of a book’s doctrinal substance with known apostolic teachings. If a book contains teachings that do not accord with the established apostolic dogma—as historically upheld by the church that Christ and his apostles founded on earth—then it is disqualified for consideration as canonical. Such doctrines include those concerning the being of God (e.g. the God of the Old Testament being the Father of Jesus in the New Testament) and the core Christian truths concerning Christ (e.g. his incarnation, perfect life, atoning death, resurrection, ascension, and future return, etc.).
4. Catholicity
The catholicity of a book speaks of its geographically-widespread acceptance among churches throughout the Christianized regions of the world in early church history. If a writing was only accepted as apostolic in a small or limited percentage of regions or churches, this criterion would bar it from legitimacy as truly apostolic.
5. Traditional Use
The traditional use of a book refers to its historically-consistent recognition among churches. If a book were not considered apostolic until the fourth century, for example, this criterion alone would rule it out. The NT books in the Evangelical canon are books that have always been considered authoritative and recognized as apostolic among the churches. Of course, there were church councils where formal recognition was given each book in our NT canon, but consistent recognition of each book is demonstrable—to greater and lesser degrees—throughout early Christian writings by the church fathers.
Contenders that were Pretenders
To illustrate how these criteria have historically been applied, below are two popular examples you may hear claimed (e.g. “The Da Vinci Code”, etc.) as examples of viable Christian writings that were “wrongly” rejected by the early church as authoritative accounts of the life of Jesus or as apostolic writings to the first century church. Upon examination, however, it’s evident why they and other similar writings were rejected.
Gospel of Thomas
Failed Antiquity: Scholars generally date the Gospel of Thomas to the second century. This dating is problematic because it means the text was written significantly later than the earthly life of Jesus or the apostle Thomas featured in the canonical Gospels. The work appears to have been influenced by Tatian’s Diatessaron, a second-century publication that harmonized the four gospels into one continuous text. The Diatessaron was not composed until after A.D. 170. The evidence, therefore, is strong that the Gospel of Thomas is far from being before or even contemporary to the gospels of Mathew, Mark, Luke, and John.
Failed Orthodoxy: moreover, the Gospel of Thomas deviates substantially from the canonical Gospels. One example is its emphasis on secret knowledge and spiritual insight, characteristic of 2nd century Gnostic belief. Saying 70 states, for example, “That which you have will save you if you bring it forth from yourselves. That which you do not have within you will kill you if you do not have it within you.” This focus on self-discovery and inner knowledge as a path to salvation is a hallmark of Gnostic heresy and strays starkly from the Christian gospel of salvation through faith in Christ’s life, death, and resurrection (Col 2:8). The short book also depicts Jesus denying females right to eternal life, simply because they are female. Such a teaching obviously departs from the elevated status of women in the canonical gospels and the apostle Paul’s soteriology, where gender neither commends nor bars a person from eternal life (Gal 3:28). As a Gnostic, apocryphal gospel, it falls painfully short of Apostolicity by failing the tests of Orthodoxy and Antiquity.
Gospel of Judas
Failed Orthodoxy: The Gospel of Judas presents a radically different perspective on Judas Iscariot compared to the New Testament Gospels. For instance, it portrays Judas not as a betrayer but as the most enlightened of the disciples who carries out a divine mission to hand Jesus over. This contrasting portrayal directly conflicts with biblical depictions of Judas as caring nothing for the poor (John 12:6) and being the “son of destruction” (John 17:12), someone “filled” by Satan himself (Luke 22:3), and a “betrayer” of the Lord (Luke 22:48).
Failed Catholicity: The Gospel of Judas also did not achieve widespread acceptance within the early Christian community. Its teachings were not embraced by the majority of Christian churches, indicating its limited appeal and acceptance.
Failed Traditional Use: Finally, this apocryphal work was explicitly rejected by influential early Christian leaders. For example, Irenaeus, a second-century Church Father, condemned various Gnostic teachings, including those similar to what is found in the Gospel of Judas, showing its lack of acceptance and recognition as Scripture within the early Church.
Conclusion
All 27 of the books in the Protestant New Testament bear the five key criteria of canonical authenticity—apostolicity that’s demonstrated by antiquity, orthodoxy, catholicity, and traditional use. This is a high bar, as it should be. These criteria both ‘rule in’ the 27 books of the New Testament and ‘rule out’ any works failing one or more criteria. ❖
