God has no beginning and no end. Therefore, he could not have been created, because this implies that he had a beginning.
You, being a finite being, could not know that empirically. It satisfies, perhaps, some philosophical quandry for you, but at the end of the day it is nothing more than conjecture.
There's nothing wrong with the answer, "I don't know," if you don't, in fact, know.
"Men never do evil so completely and cheerfully as when they do it from mistaken conviction." — Blaise Pascal