Yes, what Thal said.
Books, do you really think that everyone was running around with no purpose or direction, no rules (inner and outer), and were basically savages before the bible turned up?
And what about ethics from previous Gods and Goddesses?
The bible gave people rules from "God", but they were written by men. These men may have been transcribing/prophesying, but the bible was edited by the church... so really, you got an abridged version with bits left out that could have changed the meaning of those rules etc.
I am positive there were many people who weren't believers, and questioned the bible right from the beginning. It simply can't be true that everyone swallowed it hook, line and sinker.
And look at all that's been done in the name of God. His first rule, Thou Shalt Not Kill, was (is) ignored a hell of a lot of the time as non-believers were (are) slain (Spanish Inquisition, anyone?).