At the Reason website, Kennedy (who apparently has only one name), argues at length that atheism should be considered a religion:
[W]hether you make sense of the world as an atheist and don’t require the God postulate to complete your understanding, or you are a theist and your feelings and experiences tell you something greater is there, biologically speaking, that big blob of gray Jell-O in our skulls is like a giant arrow pointing us in the same direction. I believe that is delicious. And religious....
I contend that if your system is about God—or about the non-existence of God—God is still at the center of the argument’s “aboutness.” In the spirit of that “off is a TV channel” comment above: God is the TV. Religions are the channels. If it is off, maybe he’s dead or disengaged, but at least you admit there’s a TV....
When atheists rail against theists (as many did on my Facebook page), they are using the same fervor the religious use when making their claims against a secular society. By calling atheism a religion, I am not trying to craft terms or apply them out of convenience. I just see theists and atheists behaving in the same manner, approaching from opposite ends of the runway.
These kinds of claims are often made, but they fall apart under close inspection. Obviously, if you define the term “religion” broadly enough, atheism can qualify. But such a redefinition obfuscates important differences between atheism and religion, and is also contrary to ordinary English usage.
Kennedy argues that atheism is like religion because both atheists and theists 1) try to understand the nature of the world, 2) have beliefs about God, and 3) are often emotional about their beliefs and intolerant of opposing views. All of these points are true, but none of them prove that atheism is a religion.
It is true that both atheists and theists try to understand the world. But only the latter are committed to a religious explanation for reality, which depends on the actions of supernatural beings. The former, by contrast, can try to explain reality by natural, scientifically verifiable causes. There is an important distinction between a naturalistic worldview and one that incorporates an important role for supernatural beings.
Moreover, atheism as such is not an explanation for the nature of the world akin to various religions who explain reality by reference to God (or multiple gods). Atheism is merely a rejection of the existence of supernatural gods, which does not preclude atheists from disagreeing among themselves about the fundamental nature of reality (e.g. – some atheists are materialists, whereas others are not; some atheists even reject the genetic theory of evolution, as the officially atheistic Soviet government did for many years).
It is also true that both atheists and theists have beliefs about God. However, if believing there is no God makes you religious, then disbelieving in ghosts makes you a believer in the existence of the afterlife and disbelief in phrenology makes you a phrenologist. Both phrenologists and anti-phrenologists have beliefs about the question of whether or not feeling the shape of a person’s skull tell you something useful about their personality. Similarly, both atheists and theists have beliefs about the existence of God. I am not suggesting that all theistic beliefs are as easily falsified as phrenology (some probably are, while others are not). But rejection of theism does not make you a religious believer, just as rejection of phrenology does not make you a phrenologist.
Finally, it is certainly true some atheists get emotional about their beliefs and are intolerant of opposing views – as is also the case with some theists. But emotionalism and intolerance are not enough to qualify a belief system as a religion. If they were, then conservatism, liberalism, Marxism, libertarianism, vegetarianism, environmentalism, and many, many other views all qualify as religions too. Many of their adherents are also emotional about their beliefs, and intolerant of opposition. The same goes for many sports fans. Some North Carolina basketball fans are very emotional about their team and famously hostile to Duke fans, and vice versa. Yet being a UNC basketball fan is not a religion, except perhaps in a metaphorical sense.
To be sure, we sometimes refer to adherents of some political or moral view as having a “religious” fervor. But this is a metaphorical use of the term “religious,” not a literal one. We don’t really mean that a person with a “religious” dedication to vegetarianism is necessarily actually religious. We just mean that he has as strong a faith in his beliefs as many religious people do in God and their theological commitments.
Perhaps these terminological battles don’t matter very much. So long as we all use terms in the same way and everyone understands what they mean, it may not matter whether we define religion broadly or narrowly. However, I do worry that efforts to define atheism as a religion may obscure the genuine and important difference between atheists and religious believers: that the one view explains reality (and often morality) by reference to supernatural beings, whereas the other does not.