Why do you think that migraines cannot be proved? They are physical processes *in the head* that can be verified by a number of different techniques. They also produce verifiable changes in the brain.
Do you really want to claim that your experience of a deity is similar in type to that of the experience of an emotion or a migraine? I thought you want to claim that a deity is something *outside* of yourself, not something internal.
He just proved to himself what we have been saying all along.
That god is a condition of the mind, just like a migraine or emotion.