Biblegod, although depicted as a dick, is after all a perfect being. Which means that by definition he is worthy of worship. Now those who know me will know that I am a great lover of philosophy, and the theory of knowledge. If I can know without a shadow of a doubt that God exists, I will worship Him. However, seeing as that is impossible in this life and reality, then I will not as he has not shown himself to exist.
I push the Red button, because the condition involved knowing for certain that God exists. If he exists, as in this hypothetical situation, he must be worthy of worship due to his perfection, and there must be a reason the world is how it is (i.e. a solution to the problem of Evil)
It is just so unlikely that he does exist, that there is no way that he does. But if it was proved he existed, I'd trust Him to do the right thing for me, and push Red.