An atheist is someone that lacks faith, someone who doesn't believe in something that other people do. When you have faith, you have confidence that something is true, you rely on it and expect things to happen the way you believe that it will. You have confidence in these things and your ethics, life choices, and daily habits are all influenced by this thing that you feel to be true. But all of these things are tied up into emotion, and emotion, as any tantrum throwing child could tell you, doesn't do much to change reality.
An atheist lacks these feelings. But can we label someone based on their lack of an emotion? To be fair, there are a lot of links in any search engine where a theist will attempt to justify that faith is not an emotion, however the root of the word lies in Latin where it essentially means 'to trust', and trust is not based in reality any more than the promises of all of the ex-girlfriends that I used to have faith in. The label itself is fairly silly, but it we use it because it simplifies conversation and, at heart, primates are pretty lazy.
But what about the middle ground, can I be agnostic?
Sure, agnosticism is about knowledge. Faith is a light switch, you either have the feelings or you don't, there is no middle ground, but most people are agnostic because not knowing everything is pretty normal in our corner of the universe. There are even Gnostic Christians around, people who assert that they have evidence of God based upon the facts found in his writings, my father is one of them, but most Christians rely on faith and not knowledge because metaphor is a lot more flexible than trying to defend the biblical assertion that the bat is a bird (Leviticus 11:13-19) or any of the other inaccuracies that keep the Bible from being taken seriously as a scientific source.
A lot of intelligent scientists and atheists have labelled themselves as agnostics because they are educated enough to know the difference between the two words, but they are still atheists in that they lack faith. As a matter of fact, I would suggest to you that even considering yourself an agnostic (by the normal usage of the word) means that you lack enough faith to be counted amongst the faithful, so you automatically fall in with the rest of us. The problem here is one of perspective, people have a tendency to simplify thoughts that they don't entirely understand, so agnosticism as been thrown out there as a middle ground between those that believe and everybody else when, in reality, it's another thing entirely.
Do atheists have faith?
|Pictured: a gross over-simplification of something that most of us don't entirely understand. Not faith.|
In the beginning there was something, probably, and then something happened, we think. It seems to make sense that since we're here now that something had to cause that, and our species has collectively done a lot of work to get as much information as possible as to where we all came from, but we can only go back so far before the laws of physics break down and we aren't exactly sure what happened before that. This isn't faith because it has nuance and changes with facts, even the theories about the history of reality before that aren't considered faith because nobody believes in them. Faith is what you rely on when you don't know something, even if that feeling itself is so strong that you have certainty, it's origin are based in something else entirely. And this is why atheists are always asking for evidence, because in the absence of our shared emotion, the only thing we have to share is something tangible that might change the facts that we have accumulated about the world. Faith can be learned, it can be instilled, it can be challenged, but it is mostly used to fill in the gaps of things that cannot be known for sure, because it is disconcerting to admit that we just don't know something.
So, what is an atheist? Well, I'm an atheist, and so is everyone else who isn't born with the feelings of God (protip: everybody that has ever been born) that is, until someone convinces them otherwise. Atheism makes no claims, has no rules, is not an organization (although a branch of us are becoming a lot more organized), and accepts as default everyone who doesn't claim a specific faith. So that's what an atheist is, just somebody who doesn't feel the same way that you do. Funny how it's such a big thing.