[Serious] Could an omnipotent and omniscient god prove that he was God?

[Belacqua]

Yes, Belaqua, I understand this, but that something is generally accepted does not make it true.  I explained where this whole necessary-contingent dichotomy comes from.

I confess that I don't see yet how you're able to dismiss the necessary/contingent distinction. In itself it isn't anything demanding religion.

"This cat is a mammal" is a necessary truth, because by definition all cats are mammals. "This cat is a reptile" would be nonsense. 

"This cat is black" is a contingent truth, because it could be another color and still be a cat. 

Now how this gets applied to theology of course may be debated, but the distinction itself seems pretty unassailable.