The claim to know that no god exists is just irrational. The non-existence of any god has no evidence, let alone proof. To know something for certain there must be proof. To hold to a belief there must be evidence. Untilthen, the only actual reasonable position is agnosticism.
Lewis N. Roe, From A To Theta: Taking The Tricky Subject Of Religion And Explaining Why It Makes Sense In A Way We Can All Understand
agnosticism, atheism, belief, evidence, god, proof