It tells us that God is indistinguishable from a god that doesn't exist.So then the process is backward. Start with two, and work back. Given what we see happening in the world around us, what does this tell us about "God", if such an entity exists?
But i think you're missing the point: god-concepts exist, and this is one way to explore whether a given god-concept is reasonable. It isn't about trying to come up with a new religion; it's about evaluating the claims of the religions that already exist.