Agnosticism is a position of knowledge, it is not bound to belief in a diety. If you say you are an agnostic, you must clarify if you are an agnostic theist, or an agnostic atheist. If you do not know for 100% that God does or does not exist, you are an agnostic, whether you believe in God or not. Just saying you are an agnostic doesn't tell me anything. Are you agnostic about aliens, fairies, spaghetti monsters etc. You have to specify if you are an atheist, or a theist. Edit: Atheism is not the claim that no god exists. It is the disbelief that one does. You wouldn't say, I don't know if Santa does or does not exist, you would say you don't believe in santa claus Edit 2: Belief =/= Know or don't know. So to say, I don't believe in god, does not mean I know that no god exists.