Not only much of the New Testament is private correspondence, but its incompleteness is expressly stated, see John 21:25.
Yes, and not only that, but common sense would tell us that the Apostles who don't actually write MOST CERTAINLY go out and preach and teach to the nations. Peter and Paul were not the only apostles evangelizing! Thus, the Church history of the Apostles and their teachings is not found entirely within the Bible.
Regards
I fully believe in John 21:25, I just don't believe that everything left that was taught was necessarily true because men said so. As Jo said, I understand that the Apostles who didn't get books in the Bible nevertheless went out and preached and taught. There is no denying. So, I believe that there might be plenty of stuff that is not explicitly in the Bible that is sound under Christianity, but it must pass the test of the Bible in its totality.
My problem is that then you'll list all your traditions, ask me to prove they are explicitly unbiblical, and then, if I can't to your satisfaction, declare them as all true because your hierarchy says so. Obviously, there are a multitude of theological paradigms upon which we would disagree in interpretation, and none of us is alone in his views.
We look at the same verse and I see something different from your leaders. I can live with that, because I believe I know Who is looking out for me. I fully respect that you know Who is looking out for you, too, through the Church. I expect to learn many new teachings throughout my life (sanctification), and all I say is GREAT! I'll just be a better witness the next time. There is no inconsistency here because no perfection is claimed, due to me.