Atheism is Not a Religion, Ideology, Belief System, Philosophy
Many Christians seem to believe that atheism is a religion, but no one with an accurate understanding of both concepts would make such a mistake. Atheism lacks every one of the characteristics of religion. At most, atheism doesn’t explicitly exclude most of them, but the same can be said for almost anything. Thus, it’s not possible to call atheism a religion. It can be part of a religion, but it can’t be a religion by itself. They are completely different categories: atheism is the absence of one particular belief while religion is a complex web of traditions and beliefs.
It's not uncommon for atheists to argue that religion and theism are a sort of crutch that makes it easier for people to deal with problems in life, so perhaps it's not a surprise that some might try to turn this around and argue that atheism is actually the crutch. How, though, can mere disbelief in gods act like a crutch in any manner - no matter how metaphorical? The problem lies in misrepresenting atheism as if it were a belief system.
Many religious theists, especially Christians, resist defining atheism as simply the absence of belief in gods. There are a variety of reasons for this, but the main one seems to be that it makes it too obvious that the burden of proof or support lies with them, not with atheists. One tactic for arguing against the standard definition of atheism is to claim that atheist criticisms of theism and religion demonstrate that atheists must be acting on behalf of a belief, not mere lack of belief.
People see atheists involved in various forms of political or social activism and conclude that atheism itself must be some sort of belief system and cause. This myth bizarrely confuses atheism with the causes, interests, and goals of people who happen to be atheists. If an atheist promotes church/state separation, that's evidence of atheism being a cause. If an atheist promotes sound science, that's evidence of atheism being a cause. None of this makes the least bit of sense.
The most visible form of atheists' activism is probably arguing against the value of religion and theism. More and more atheists are standing up to not only publicly admit that they are atheists, but also to say that neither religion nor theism have anything to offer which makes them very necessary or attractive. People can not only lead good, interesting, and meaningful lives without them, but might in fact be better off if they try. Does arguing against religion mean atheism is a religion?
It is true that many atheists work together for different causes and seek some of the same sorts of changes or developments in society. Does this therefore mean that atheism is a 'belief system'? Well, that would be like saying that 'female' is a belief system because women work together for certain causes and seek some of the same changes in society. Is 'female' a belief system? Of course not, that's nonsense - and so is the claim that atheism is a belief system.
Because of atheism's long-standing association with freethought, anti-clericalism, and dissent from religion, many people seem to assume that atheism is the same as anti-religion. This, in turn, seems to lead people to assume that atheism is itself a religion - or at least some sort of anti-religious ideology, philosophy, etc. This is incorrect. Atheism is the absence of theism; by itself, it isn't even a belief, much less a belief system, and as such cannot be any of those things.
Many Christians seem to believe that atheism is a religion, but no one with a fair understanding of both concepts would make such a mistake. Because it's such a common claim, though, it's worth demonstrating the depth and breadth of the errors being made. Presented here are the characteristics which best define religions, distinguishing them from other types of belief systems, and how atheism utterly fails to even remotely match any of them.
