[adiaireton8]

The Catholic argument for the teaching authority of the church is indeed derived from Scripture

So between the time that Christ ascended, and the time the first book of the NT was written, when the Apostles were asked to provide an argument for the teaching authority of the Church, they were speechless?

You are obviously not Catholic.

-A8

[Wallace T.]

The proof of certain Catholic doctrines is Scripture; others derive from tradition, which ultimately was reduced to writing by the pre and post-Nicene Fathers, though mostly after the New Testament was written. Obviously, Peter, John, Paul, etc., would have stated that, say. Jesus Christ was fully God and fully man because they heard it from Him during His life or, as in the case of Paul, he received the information through direct divine revelation. It all boils down to God's Word, whether given directly or written down for the benefit of the generations succeeding the Apostles.