I would think that most people are agnostic. Of course you have preachers and others who devote their lives to their particular religion who are purely Gnostic Theists but I feel that most logical people would at some point have to admit that there is zero hard proofs to their particular beliefs. I was raised Christian but over time my beliefs diluted to believing that there very well might be some higher power out there. However this higher power has never once tried to connect with me, and I've never seen any good proof to suggest that there might be so I'm open to the idea of there being no god. Part of me wants there to be a higher power, that my conscience and stream of existence is far more than just an illusion caused by a super computer in my head, but maybe that's just merely childlike imaginings.
I personally hate Gnostic Atheists...I can imagine everyone of them is smug. I'm stereotyping and generalizing..but I find absolutely 0 reason to be so certain that there is no god, when we have barely touched upon the mastering of knowledge.
Of course! While it's easy to suggest that religion was created for the sole purpose of finding explanations for things that we have no knowledge for, we still do not know absolutely everything. To claim with absolute certainty that we know anything is smug in its own right. Especially in religious terms, that's annoying.