Yes, I made that statement. There were hundreds of scrolls of various "gospels" circulating in the developing Chirstian world, especially those written by Gnostics. Such Gnostic "scriptures" were interspersed throughout churches and read in public, masquerading as apostolic writing. The Church had to separate the inspired from the profane.
How would you define "prevail" without scripture?
The Church did not just "memorize" and verbalize. The entire liturgical life of the Church from the beginning contains the same faith you find in the NT. All you have to do is follow liturgical texts and practices dating back to the beginning and you will find what's in the NT with OT references included.
You could learn the entire NT by reading all available liturgical texts that pre-date compiled NT. These liturgical texts were written and worship tailored around them based on the Apostolic knowledge of the faith, which is why the Church, and the Church only, could separate Gnostic forgeries from genuine gospels and epistles.
Yes, I have no doubt that one of the main and immediate benefits of the scripture was to pour cold water on all the error that was circulating at the time. My "beef" was about the idea that it was men who DECIDED to compile the scripture into the Bible. I would say that God ordained it from the beginning, so it was really His decision.