Second Timothy 3:16-17 declares that “all Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work.” It is clear that the early church regarded the Old Testament as inspired Scripture. As 2 Peter 1:20-21 explains, “Above all, you must understand that no prophecy of Scripture came about by the prophet’s own interpretation. For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the Holy Spirit.”
But can this be equally applied to the writings contained in the New Testament? Were the New Testament writers aware of the scriptural nature of their epistles? Although this cannot be proven definitively, there is a fairly strong case to be made that they did. In 2 Peter 3:15-16, Peter writes, “Bear in mind that our Lord’s patience means salvation, just as our dear brother Paul also wrote you with the wisdom that God gave him. He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable men distort, as they do the other Scriptures, to their own destruction” (emphasis added). Clearly, Peter regarded the writings of Paul as inspired Scripture.
A further indicator that the New Testament writers understood their writings as Scripture is in 1 Timothy 5:18, wherein it is declared, “For the Scripture says, ‘Do not muzzle the ox while it is treading out the grain,’ and ‘the worker deserves his wages’” (emphasis added). While the first reference is taken from the book of Deuteronomy (25:4), the second is derived from the Gospel of Luke (10:7). Clearly, Luke’s writings are being viewed as similar in authoritative value to the Pentateuch. Luke’s writings are also here referred to as “Scripture.”
In conclusion, there are good grounds for believing that the New Testament writers viewed each other’s writings as sacred Scripture, literally inspired by God – “and useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work” (2 Timothy 3:16-17).