Since the word "canon" derives O from a Greek term signifying "a rule or standard," a study of the Canon of the New Testament involves the examination of how certain Christian writings grew to be rightfully considered as the standard or norm for Christian faith and instruction, forming eventually what we term the New Testament. It is, then, a mistake to suppose that the New Testament, closely integrated as it seems to us, originally appeared in its present form. Each of its twenty-seven books was written separately, but as time went by they demonstrated individually their inherent worth, and came to be closely associated in the thoughts and affections of Christian folk.
The letters of the Apostle Paul are felt to be the earliest complete documents now preserved in our New Testament. At first there was no thought of placing them on a par with the Old Testament, the only canonical scripture then known, but in course of time they came to be read at the same services which included readings from the Old Testament, and so gradually advanced towards canonicity.
From the very first, the Gospels must have been considered of vital significance as containing the records of the Master's life and the basic statements and proofs of Christianity. Writing about the middle of the second century, Justin Martyr thus bears witness to the intense interest shown in the "memoirs of the apostles"—a phrase usually understood as signifying the Gospels: "On the day called Sunday, all who live in cities or in the country gather together in one place, and the memoirs of the apostles or the writings of the prophets are read as long as time permits" (First Apology of Justin Martyr).
