I think you either beleive or you don't. What would the midlle ground be? Nonexistence? There doesn't seem to be room for much more.
Yes, they could be in a state of cognitive dissonance, or could be experiencing difficulty in a transition from theism to atheism.
Not everyone should be under the tyranny of the burden of being intellectually honest at all times. A crisis of this magnitude sometimes requires a rejection of "shoulds" and a temporary pass to try to transition through it in the least jarring way possible.
Yeah, well, by that logic your doormat is atheist. It doesn't believe. So are the dust bunnies under your furniture. I don't mean to pick on you specifically as many seem to follow this logic, but I think clearly we want a little more than this. You have to be capable of holding a belief (which means no nutter Xians will be chasing your doormat and dustbunnies down with pitchforks and torches), AND you have to have considered the question, I think, to be either a theist or an atheist.
If one is an atheist simply because he has never heard of god, he is more than likely ripe pickings for the next convincing-sounding evangelist.
Apatheist: you don't care enough to pick.