The bible is an exquisite corpse. Know what that is? It is a story begun by one person which is continued by a second and passed on to a third without any of the participants consulting as to outcome.
http://en.wikipedia.org/wiki/Exquisite_corpse
Anybody can build on what preceded, but, can also shape and move the narrative according to whim.
The big problem all of us have (now that the bible canon has been closed a while) is pretending there is only ONE mind and purpose behind any of it. That and that alone is the source of the greatest confusion involved in parsing "meaning", "messege", "intent", or "value".
The false premise that one divine mind is explaining something which is vital to us keeps us racing like a hamster in an exercise wheel.
Almost everybody who approaches scripture has a go at making sense of it. There are quite literally tens of thousands of nuanced explanations, explications and analyses that have poured out of enquiring minds over the centuries.
But, there is nothing behind this "exquisite corpse" other than imagination and arbitrary caprice.