I feel like this is one of those awkward debates where both of us actually agree on the topic at hand, yet we both use clever wording which forms a distinction between our points that allows the debate to actually continue...

I'll continue our little agreement/debate:

"I don't believe in God because I've seen no evidence a god exists" is along the same lines as making the assumption that X + 40 = 42. Unless you know the value of X you shouldn't consider your answer to be correct.

"I don't know if God exists, or in what manner or form God may or may not exist because I've seen no evidence a god exists" is comparable to saying X + 40 = Y. You don't know the answer so you leave it as a variable.

(X + 40 = 42) != (X + 40 = Y)

Atheism is a belief based on a lack of evidence and parallels religious belief.