Atheism and religion are often portrayed and treated as polar opposites; although there is a strong correlation between being an atheist and being irreligious, there is no necessary and inherent connection between the two. Atheism is not the same as being irreligious; theism is not the same as being religious. Atheists in the West tend not to belong to any religion, but atheism is quite compatible with religion. Theists in the West tend to be religious, but theism is compatible with irreligion.

To understand why, it is necessary to keep in mind that atheism is nothing more than absence belief in the existence of gods. Atheism is not the absence of religion, the absence of belief in the supernatural, the absence of superstitions, the absence of irrational beliefs, or anything else along those lines. Because of this, there is no inherent barrier preventing atheism from being part of a religious belief system. It may not be common, but it's not impossible.

So why does the confusion exist? Why do so many people seem to reflexively assume that atheists must necessarily be irreligious, if not anti-religious?

Quite simply, most religious belief systems (especially those dominant in the West) are theistic — they include belief in the existence of at least one and this belief is often a central, defining characteristic of that religion. It would be very difficult (and probably impossible) for a person to combine atheism with adherence to such a religious faith because doing so would require redefining the religion to such an extent that most members might not recognize it anymore.

This is likely the reason why you will even see some atheists assuming that theism and religion are so deeply intertwined that they won't bother to distinguish between the two, using the labels almost interchangeably. However, just because most religions we encounter incorporate theism, that shouldn't lead us to assume that all religions are therefore necessarily theistic. Just because atheism is incompatible with the sort of religion we are used to seeing doesn't mean we are justified in concluding that it's compatible with all possible religions.

Defining Religion

It would be incredibly ethnocentric if we allowed ourselves to define religion in general solely based on our encounters with a couple of specific (and closely related) religions like Judaism, Christianity, and Islam. There is a much wider and more varied religious universe out there than those three faiths represent, and that's just taking into account3 religious which exist today, never mind all the religions which have existed throughout human history. Religion is a human creation and, as such, it is just as varied and complex as human culture generally is.

For example, many forms of Buddhism are essentially atheistic. At most they regard the existence of gods as possible, but often they dismiss gods as simply irrelevant to the important task of overcoming suffering. As a consequence, many Buddhists not only dismiss the relevance of gods but also the existence of gods — they are atheists, even if they aren't atheists in the scientific, philosophical sense that many atheists in the West are.

In addition to old and traditional religions like Buddhism which are accessible to atheists, there are also modern organizations as well. Some humanists call themselves religious and many members of Unitarian-Universalism and Ethical Culture societies are also nonbelievers. Raelians are a relatively recent group which is recognized as a religion legally and socially, yet they explicitly deny the existence of gods, making them "strong" or "gnostic" atheists.

There has been some debate as to whether such forms of humanism truly qualify as religions, but what is important for the moment is the fact that atheist members themselves believe that they are part of a religion. Thus, they do not see any conflict between disbelieving in the existence of gods and adopting a belief system which they consider a religion — and these are, without a doubt, atheists in the Western sense of scientific, philosophical atheism.

The answer to the question is thus an unequivocal yes: atheists can be religious and atheism can occur in conjunction with, or even in the context of, religion.