Heck, if such a being exists why is this universe usefull to him at all?
It could have various uses:
1. God might have created the universe out of boredom. It must be pretty boring to be the only thing that exists.
2. Or, more poignantly, He might have created the universe because he needed somebody to love.
3. On the other hand, according to Christian tradition, He wants us to believe in Him. He seems to clamor for one's belief so urgently that one suspects that He needs our belief in order to convince Himself of his own existence.