It has always been my understanding that the process of official recognition (canonization) was affirming already held beliefs--not actually changing anything. Of course there were a few books on the bubble.
Quote:Writings attributed to the Apostles circulated among the earliest Christian communities. The Pauline epistles were circulating, perhaps in collected forms, by the end of the 1st century AD.[a] Justin Martyr, in the mid 2nd century, mentions "memoirs of the apostles" as being read on "the day called that of the sun" (Sunday) alongside the "writings of the prophets."[5] A defined set of four gospels (the Tetramorph) was asserted by Irenaeus, c. 180, who refers to it directly.[6][7] https://en.wikipedia.org/wiki/Developmen...ollections