So how can that be? That those presumably derivative texts know more about Christianity than the authoritative text, which you say is not worth the paper? Here, I'll guess: They're making stuff up. Rationalizing, trying to put a chaotic mess into some sort of order, but in the process injecting a lot of themselves.

So it comes down to, read your favorite author and believe what you want. Which is not going to go down well with a lot of people.