Canonization simply stated is the process by which certain books became officially recognized as the authentic “God-breathed” Scriptures.
Canonization is a fascinating topic but as far as I understand it, it may be better to view it as a process rather than just a consensus. Clearly it took several hundred years of discussion before the church settled on the 27 New Testament books we now consider Scripture. Canonization was not achieved by people meeting together to discuss and determine which books to include in the Bible. This process occurred at different times and in different places over several hundred years.
The fact is that none of the church councils actually made a book canonical. The council could merely affirm that a book had already been used from the earliest history of the church and that it could continue, in fact, to be so used.
Gradually the church began to draw boundary lines on which books to include and which to exclude as Scripture.
There were several criteria that church leaders used to determine which books would be included in the canon. Some of these were antiquity and apostolicity – was the book written by an apostle or someone associated with an apostle. Another test was that of orthodoxy – was the writing in line with traditional church doctrine from the beginning of the church age. Another was, yes, consensus – did many churches in many different places use the book.
Clearly many of the books were recognized as authoritative even before some council voted on them. The council was merely ratifying what was already customary. But the bottom line is we still need to leave room for the realization that we must ultimately trust that God was the guiding force behind the scenes that directed his people on which books to include in the canon.
It’s kind of like the question did Paul write Ephesians or did God (the Holy Spirit) write it? It was both. So did man decide which books to include in the Scriptures or did God. Again, it was both. So, was a consensus involved in determining which books to include in the canon? Yes, but not in the traditional way we view consensus.