If the NT writers were citing other NT writers as Scripture, then that suggests the canon was not a later ecclesiastical development, but something early and innate to the early Christian faith. And that is a basic fact that all Christians should know.

One of the most controversial issues in the study of the New Testament canon is the date when these books were regarded as Scripture. When were these books first used as an authoritative guide for the church? Critical scholars will argue that these books were not written to be Scripture and were not even used as Scripture until the end of the second century.

But one of the most basic facts that Christians should know is that some New Testament writers actually quote other New Testament writers as Scripture. This demonstrates that the concept of a new corpus of biblical books was not a late development, but one that seems to be present in the earliest stages of Christianity.

The most obvious example of this phenomenon is 2 Pet 3:15-16 where Peter refers to Paul’s letters “Scripture” on par with the books of the Old Testament. It is noteworthy that Peter mentions multiple letters of Paul, indicating that he was aware of some sort of collection. And, even more importantly, he assumes his audience is aware of this collection as well. There is no indication that the scriptural status of Paul’s letters is a new or novel idea—Peter mentions it quite casually and naturally.

The implications of Peter’s statement should not be missed. It shows that apostolic letters (in this instance Paul’s) had a scriptural status in early Christianity. If so, then it hard to imagine Peter would not have expected his own letter to be received with the same authority. After all, just a few verses earlier Peter made it clear that the teachings of the apostles were on par with the Old Testament itself (2 Pet 3:2).

Another example of this phenomenon is found in 1 Tim 5:18 which says: “For the Scripture says, ‘You shall not muzzle the ox while it treads out the grain’ and ‘the laborer deserves his wages.’” While the first quote comes from Deut 25:4, the latter quote is an exact match with Luke 10:7. Although one might suggest that Paul is citing oral Jesus tradition, that option is precluded by the fact that he introduces the saying with “the Scripture says.”

Although Paul might be citing some unknown apocryphal gospel (that just happens to have the exact same wording of Luke 10:7), why should we prefer an unknown hypothetical source over a known source? We know that Luke actually was used as Scripture in the early church—the same cannot be said of this hypothetical apocryphal gospel.

Of course, because these two passages seem to cite other NT books as Scripture, scholars have argued these books are forgeries, having a late date probably around the turn of the century (c.100). We cannot delve into these academic debates here, but it should be noted that these debates are by no means settled. Moreover, even if one concedes the late date for these books (for the sake of argument), that still puts the date of the canon at a remarkably early time.

If the NT writers were citing other NT writers as Scripture, then that suggests the canon was not a later ecclesiastical development, but something early and innate to the early Christian faith. And that is a basic fact that all Christians should know.

Dr. Michael Kruger is a Teaching Elder in the Presbyterian Church in America and President of RTS Charlotte were he also serves as a Professor of New Testament. This article first appeared in his blog, Canon Fodder, and is used with permission.