What does it mean to say "To you there is a God, to me there isn't?" Either there is or there isn't, and one of them is mistaken. The same proposition cannot be both true and not true. Either the is a cat in this room or there is not; either there is a God or there isn't. What is "To you there is, to me there isn't" except a confusing and perhaps dishonest way of saving "according to you there is, according to me there isn't that is, "You believe there is, I believe there isn't' thus leaving it an open question which of the beliefs is true.