another thought...
I someone today wrote a book to be added to the bible and said God told him to do it...what would be said? we'd call the guy a freak, some of us might think it was great advice, but hardly God given or nothing we couldn't figure out on our own.
I don't know that I have that much confidence in the guy 2000 years ago without electricity scratching on some paper with a piece of charcoal telling others about the meaning of life. But I do have some confidence in the refined, rewritten, and recycled writings of those guys that have been infused with common sense as well as experience since then.