Without citing the bible, what marks the bible as the one book with God's message?

[Whateverist]

I've heard of lots of scholarship being done to establish the existence of persons with the right names inhabiting the right places at the right times. But lets cut to the chase. Suppose there was a Mary and a Jesus and a Paul and Sneezy and Rudolph and whoever else the bibles says is part of its story. Lets go ahead and grant you that the stuff the bible says happened is right too - within reason. I can't grant you a talking snake, God speaking from a burning bush, a man living in a whale, a resurrection, a flood covering Mt. Everest, the story of creation or anything else that suggests the supernatural. But I will grant, for the sake of argument, that every natural event described in the bible is historically accurate.

Given that, why should anyone believe the bible is the word of a supernatural god? Why should anyone think its god exists at all?

Okay Christians, again only for the sake of argument, lets suppose that god does exist and the bible records an attempt on its part to communicate with mankind. How do you justify a literal reading of the bible? Perhaps a poetic reading was intended, not by the scribes, but by your god. If this god of yours is as ineffable and other worldly as is claimed, why would you think that such a being could communicate with beings as limited as ourselves in any way other than parables and poetry. You may really be missing the whole message by concretizing the poetic.

Remember Christians, the challenge is to justify 1) that the bible is the special book and 2) that a literal interpretation is the one intended by your god .. without (for obvious reasons) citing the bible itself. I await your guidance.