I'm not talking about just knowledge. If someone said "Well, the Earth isn't flat, but there could be planets that are flat, but we just can't see them." we are going to reason, based on what we know and believe, to decided if that claim is likely to be true. Are you on the fence regarding the existence of Zeus, Apollo, Athena, etc? Sure, there's an explanation for the universe but, given that there is no non-circumstantial evidence for any god that man has created, why would you automatically go that route?