The Genesis allegories from 1 - 11 are based on Babylonian stories that were adapted by the Hebrew people during their period of captivity.
They were passed down via oral tradition for many generations, until the Hebrews developed a system of writing, roughly around 1000 BC.
Moses is attributed with the compiling together of the early allegories and histories that make up the first five books of what Christians refer to as the Old Testament. He did not "write" them himself.
While the faithful believe that the Bible is inspired by God, and does contain many moral truths, it most certainly was not "dictated" to mankind by God.
Jesus was God and walked on the Earth for 33 years, so if we were supposed to get direct messages from God, WHY DIDN"T HE WRITE ANYTHING DOWN????
p.s. Moses fans: Moses was pretty clear about receiving the Ten Commandments from God, and his role in the Exodus, but he NEVER mentions anything at all about receiving all this "dictation" from the Almighty that he supposedly "wrote" for the Hebrew people. Why not? If it in fact, happened the way you believe it did, then why isn't it mentioned anywhere at all?