Establishing the Canon of Scripture

Useful insight into a pattern of church history here -- accepted authority exists, then there's a challenge, and it becomes formalized:

"The canon of Scripture wasn't a real point of ambiguity even though it was not formally fixed for a few centuries, and then only because what was commonly held was challenged by some. The general agreement prior to that made a formal statement unnecessary. That's been the pattern throughout church history. Some things just aren't officially stated until it's under challenge. That's not to be mistaken for lack of a clear position prior to the formal statement. ...

F.F. Bruce explains well in his book The Canon of Scripture that the books of the New Testament were accepted quite early based on apostolic authority. The practices of the early church, how they used these books in church services and to get authoritative teaching, demonstrate that there was an early consensus about the canon. Other writings were sometimes used as sources of devotional teaching or encouragement, but the practice of the church elevated the books later formalized as the canon very early. It wasn't a decision that was left for centuries; it was only left to make official what was practiced. The sorting out of canonical Scripture from other writings was done very early and these books were used by the church as Scripture on par with the Old Testament books as God's Word."

I think the same thing was true for the challenges that led to the 1st council of Nicea.