I'm in no way married to the idea I put forward - it's just one that was floating around my head, and it clearly needs some further thought and refining. However, I maintain that the primary issue here lies not in the labels 'atheist' or 'theist', but instead in the definition of god. That's the issue I'm trying to tackle at the moment...
That's kind of the point I was trying to make with my questions about my socks.
We're so used to thinking of "god" as some minor variation of the all-good all-powerful all-knowing invention which is impossible to reconcile with reality that it seems easy to reject the possibility of god's existence and settle comfortably into calling ourselves atheists.
I (and I suspect a lot of people) am (are) only comfortable claiming that label in relation to a specific definition of god. If you'll define what "god" is, I'm more likely to be able to tell you whether or not that's something I "believe."
"Atheist" is an extreme position -- "I don't believe in ANY definition of god." Even if you add "because I have no evidence," and leave open the possibility of belief if such evidence becomes available, you're implicitly rejecting a lot of potential definitions for which "existence" is well-supported by evidence. What if god is gravity, or consciousness, or life itself, or the whole cosmos? Then the question is not so much whether such things exist, but whether it is meaningful to attach labels like "god" to them.
"Theist" is also an extreme position. "Belief" implies something. If you believe I'm wearing a warm pair of socks, you leave yourself open to a whole host of questions (When did I don them? What color are they? Wool, synthetic, or other? Thick or thin?) for which the only honest answer is "I don't know." I claim that "I don't know" is actually the more honest answer to the first question, and that "No" leaves you open to an equally problematic set of questions which will ultimately have you saying "I don't know" in answer to a question about belief, not as an evasion, but as the most honest answer you can give.
Words are just fuzzy placeholders we can use to convey meaning. If Tom has in mind some concept of a deity, and thinks "theist" (or deist, or pantheist, or monotheist) is the most honest way to describe himself, Harry has no right, in my opinion, to claim he's not a real theist just because Harry's own concept of a deity differs from Tom's.
If belief was an absolute thing (you either believe, or you don't), then our courts wouldn't have different standards for it -- "belief beyond a reasonable doubt" vs "belief based on a preponderance of the evidence," for instance.
There are believers, and there are non-believers, and there are people who don't feel themselves pulled strongly enough in either direction to adopt either label. I think it's more meaningful to let them speak for themselves and listen to what they're saying than it is to insist that they're talking nonsense based on some hard-line definitions we picked up in a philosophy class. Certainly, it's more productive.
But I'm willing to continue discussing it, if you're willing to tell me what you believe about my warm socks.