Because God did not explicitly
reveal what books are the
inspired books of the Bible,
title by title, to anyone, we must look to His guidance in discovering the canon of the Bible.
No book of the Bible says that
it is part of the Bible.
Jesus has told us that he has
not revealed all truths to us.
John 16:12-13
I
have much more to tell you, but you cannot bear it now. But when he comes, the Spirit of truth, he will guide you to all truth.