Ontology

• He is all-encompassing
• He encompasses the current thought that He is all-encompassing
• This thought could be considered real or unreal
• If the thought belongs to the real world, He exists in reality
• If the thought belongs to the unreal world, He must exist in the world outside this unreal world i.e. encompassing the real world given that He is all-encompassing => He exists in reality
• Ergo He exists!

Godel's Proof:

 Let us call it the argument from omniscience.

• God is understood to be an individual or being who knows everything, i.e., is omniscient. If something is true, God (real or fictitious) would know it. Similarly, if something is false, God (real or fictitious) would know that as well. Along with this goes the fact that we conceive of God as encompassing all rationality. A being who created the universe but was irrational, for example, would not appropriately be called God.
• All rational individuals believe in their own existence. Even if they don't exist, this is presumed to be the case. Popeye is conceived of as believing in his own existence. He is simply mistaken about this fact. Existing individuals believe correctly in their own existence, while fictitious individuals are sadly mistaken on this point.
• If God did not exist, then by our first point, above, God would know that he or she did not exist. But this contradicts our second point. So God must exist.