Dude, you're venturing into some dangerous territory making a game about the bible. I don't mean in terms of people getting mad, which of course some fantatics might, but this is the internet. More, you have to make sure that what you're doing is in the spirit of the bible in one way or another. For example, I'd argue that an RPG about Jesus would inherently suck because the RPG genre has absolutely nothing to do with the New Testament. Sure, you could give all the disciples different spells and skills etc etc and make a cool party system - but then there's the problem of Jesus: He doesn't fight. I mean, he gets mad, knocks over a couple money changer carts and what have you, but on the whole a game in which a basic mechanic is battle, Jesus would be completely out of place as a lead role. I mean, he drives away the devil by quoting the Old Testament - not to mention the fact that if you're adapting the bible's story, you've got four gospels all telling you different versions of Jesus and leaving you going fhsdgfhydsfsd WHICH ONE IS REAL?? And I mean, if you're going for John's Jesus, he can do just about anything.
So, unless you've got another genre in mind, the New Testament is out right off the bat.
Now Moses, he'd probably kill a dude or two.