for this issue alone, i choose to adhere to a very strict definition of "evidence", and one that does not include facts that are basically inferences from human sciences such as psychology and anthropology. the reason for this is i think the "can't prove either" scam is best disposed of when sticking to real factual arguments. it'd be way too easy for any believer to "prove" psychological traits are actual tell-tale signs of god's existence. it'd be way too easy for any believer to put your assumptions that "nothing is real until proven" on the same level as "an act of faith is needed to see". i think you can get tricked more easily if you allow rethoric or anthropologic arguments to be introduced in the "pure" existence vs. non-existence debate.
the fact that i, as an agnostic, accept the possibility of god's existence clearly clashes with the absence of rational evidence you mention, and i know it. but i consciously allow doubt to permeate me in order not to derogate from a strictly "logical" course of action. that same course of action tells me that as long as i have no technical evidence of a statement's falsehood, the most i can do is refrain from believe it true. and that's exactly what i do.
rahvin.