Where exactly do you see that? Where, beyond a sola apologetic? How do you know that your scenario is what happened?
Easy, it is implicit in Scripture, in which men discerned what is of God versus what is not, without an infallible magisterium. Do you deny that? Tell me how the Scriptures, by which substantiation the NT church established Truth claims upon, came to be established as authoritative Scripture.
And how come you did not answer my questions?