They said the present period is poor in Spirit, and therefore we must always return to the classical period. The Apostolic period is the classical period of Christianity, and what has been written at that time is valid for all times. – We shall see later that this statement was not always acknowledged by Christian theology, but here it was for the first time really fixed. Therefore something really new cannot be canonic.
This was one of the reasons why we have in the Biblical literature so many books which go under Apostolic names, although they were written in the post-Apostolic period. But that which is canonic, is canonic in an absolute sense, even in the letters of the text. Here Christianity simply followed the legalistic interpretation of the Law in Judaism where every Hebrew letter of the Old Testament text has an open and a hidden meaning, and is absolutely inspired. But this was not enough – as it never was, either in Protestantism or in any other people in which the Bible was made the ultimate norm..–..because the Bible must be interpreted. And the GnostIcs interpreted the Scriptures differently from the official Church. Another principle therefore must enter: TRADITION. The tradition was identified with the regula, the rule of faith. When this happens, not the Bible but the rule of faith becomes decisive, exactly as the creeds of the Reformation 50 years and later ,after the Reformation, are the decisive canon for theological teaching, and not the Bible.
The rule of faith was also called the canon of truth, and it is true because it comes from the Apostles. It is traditio apostolica , apostolic tradition, which is mediated through the presbyters or bishops. This however, is still too much. There are many elements in the tradition, ethical and dogmatic, so it must be concentrated in one creedal form, and the summing up of the Bible in the rule of faith and the rule of faith in the creed, was made in connection with baptism, the main sacrament of that time. The confession of baptism is the creed.