What does it mean to be atheist?
What, in your opinion, is the single-most compelling reason to be an atheist, if there is one?
Hello, vac_id,
Welcome to the forum. 
Are you an atheist?
~Just curious.
Here's the thing, I think I am, but I'm not sure. It's confusing to me because there does seem to be a distinction that people don't often make between the concepts of "believing something is true" and "having a concrete reason to think something as true". For instance, someone might claim to believe something, but their actions would indicate that they think otherwise - or, inversely - someone might claim not to believe something while their actions similarly betray them. Why is this? Because there's some dissonance between their beliefs and what they can reasonably regard to be true, given their understanding and experience. When someone doesn't act in accordance with professed beliefs, what is the reason for that? Some say that it is that they don't "really believe what they say the do", but it's more complex than that. Possibly they believe, but they also, more rationally, doubt their beliefs or their validity. People are both rational and irrational and some have a preference for acting upon rational thinking and for others they may have a preference for acting upon irrational, beliefs despite rational reasons for actually thinking such beliefs are true.
I don't buy the idea just yet that there are people who really do suspend belief in things they can't rationally believe to be true, but I'm still open to the possibility.
You see, I think I believe in God, but I also acknowledge that I have no concrete reason, no tangible reason, to believe that this is true. One person might attempt to correct me and say that I actually do not believe in God, because it doesn't make any sense for me to believe something I don't actually think of as being true. Another might say that I'm superstitious, that I do believe in God even if I know better that I have no reason to. Still others would look at what I do and infer what my true thoughts or beliefs must be, with the assumption that I might say I believe or think one thing, but do another, so I must not really believe or think that thing. But it's confusing because there's so much ambiguity in the concept of a belief. What exactly is a belief? If one were to Google the word, belief, this is what comes up:
1.
an acceptance that a statement is true or that something exists.
"his belief in the value of hard work"
2.
trust, faith, or confidence in someone or something.
"a belief in democratic politics"
Neither of these is the same as <i>thinking</i> something is true. This leaves room for "accepting" or having "faith" that something is true, despite thought to the contrary.
I think self-professed agnostics are a subset of atheists, given such a definition of atheism being "not holding a belief in a creator", but then we're all agnostics if we conflate the idea of belief with thinking something is true. Christians and members of other faiths have "faith" that something is true. They haven't logically deduced that what they believe is true, so they don't actually <i>think</i> that what they believe is true. So are the religious also agnostic? But then they would be atheists as well.
So why do so many people argue over who's correct when we all essentially agree on the same points, but use different terms or apply different emphasis?
It's like, "I don't KNOW something is true, but I BELIEVE it to be!" What does that even mean? It's not necessarily that someone saying this is outright lying; although they might be, if not to who they're speaking to, then possibly themselves; but that there really is a nuance between literally thinking something is true and believing that something is true.
So who is a proper atheist? Someone who says "I don't believe in God" because they don't think there is a God? Someone who says "I believe in God" when they still can't reasonably think there is a God (at least by the same reason the other would use)?
And people can't simply choose to believe other than they do. An atheist can no more force themselves to believe in God if they don't than a theist can force themselves to disbelieve in a God if they do.
So, I'm just trying to work this out.
The idea of believing something is so complex to me, because someone could deny believing something by virtue of the fact that they acknowledge that they have no reason to think something is true. But does that mean that they don't believe? That they don't act as if something is true despite not having sufficient evidence to conclude that something is true?