Here is my best attempt to prove that God doesn't exist:
(1) I exist, and I'm not God, therefore, God is not omnipresent. (God is not me, so that is one 'place' that is not God).
(2) Evil exists, therefore, God is not omni-benevolent. I don't find the argument that God has a long-term plan convincing. Disaster is not a long-term plan. And nature could exist as a result of a learning process, so there is no NECESSITY to believe the Ontological Argument for God.
(3) By the time someone such as God is omniscient, there is necessarily more to know than before: one level of omniscience leads to another level of omniscience (as in Godel's incompleteness). Therefore God is either infinite, or he is NOT omniscient. But since he is not omnipresent or omnibenevolent (benevolence would result from being infinitely powerful), therefore he cannot be infinite, so he cannot be omniscient.
(4) A God who does not prevent all disasters is not omnipotent, since preventing disaster is what omnipotence is good for. And an omnipotent being who was a creator of his creation would prevent disaster if it was easy to do. So, again, he is not omnipotent.
(5) Conclusion: God doesn't exist in the sense of omni-presence, omni-benevolence, omni-science, or omni-potence, therefore he doesn't exist at all. Better bets are atheism or limited polytheism.
On the other hand, God might cause everything to exist just as it is BY SHEER COINCIDENCE OF JUSTICE. In that case, God would be an artist that improves things outside himself. But since these 'creations' are evidently not God, then necessarily God would not be omnipresent, and therefore the other arguments would follow.
Or, you can conclude that God is imperfect, even though he has all the properties of being God.
International Society for the Philosophy of Architecture » Ethics and Aesthetics of Architecture and the Environment