Is atheism a religion?
Is atheism a religion? is a question atheists are often asked, although it's sometimes not asked, but rather stated, "atheism is a religion." I understand the confusion because there are several points of commonality between the two: some atheists "religiously" hold gatherings where they have "communion" with each other and discuss belief in gods, souls, and the supernatural, and frequently "evangelize" their position and try to "convert" people over to it. To many people, this behavior is very similar to the behavior of religious people, so they conclude that atheism is a religion. However, while there are surface similarities, atheism is dramatically different from a religion.
Religions believe in the supernatural and hold rituals
While all religions are different, they do share two common traits: the belief in some form of supernatural phenomena (gods, spirits, afterlife, etc.) and an adherence to ritual (prayers, rites, tenants, etc.). Atheism is merely the lack of a belief in gods; there are no supernatural beliefs or rituals of any kind.
Generalizing the word "religion" too much makes it meaningless
If the word "religion" just means people gathering together to discuss any shared interest, then suddenly everything becomes a religion from fantasy football leagues to scrap-booking groups. Of course, very few people would understand these activities to be religions, and certainly wouldn't think of them when the word "religion" is used. When someone asks, "what religion do you believe," we understand that they're asking about Islam, Christianity, and the like, not about our hobbies or political beliefs.
Religions are opt-in
Excluding the most violent adherents, most religious people accept that a person is only religious if they actively choose to be. Thus, a Hindu is a Hindu because they have decided to adhere to the tenants of Hinduism, and those who do not follow the Hindu religion are not Hindus by default. Atheism is the default position when a person doesn't follow any religions. A more pithy way to say this is, "atheism is a religion like not collecting stamps is a hobby."
Some religious people are atheists
To add to the confusion, some religions, like certain forms of Buddhism, do not believe in gods. Therefore, those Buddhists are technically atheists even though they believe in souls, pray, and religiously perform rituals. Of course, religious people rarely identify as an atheist, because they equate atheism with being non-religious even though it technically isn't.
You can debate a belief without believing in it
This should go without saying, but a common argument used by those who assert atheism is a religion is that atheists often talk about belief in gods. Of course, just how political pundits can criticize liberal politics without being a Liberal, so too can an atheist criticize theism without being a theist.
Having a building doesn't make an organization a religion
It is sometimes pointed out that atheists have their own churches, like Sunday Assembly, which meets regularly in dedicated buildings. Of course, these can't be churches because, by definition, a "church" is a building used by Christians. For the same reason, they can't be temples, mosques, or anything other word solely attached to a specific religion. However, the fact remains, these buildings still fulfill community roles in a manner similar to a church. But is that all a religion is? An organization that has a building where people regularly meet? Many cities have community centers where people regularly meet, but that doesn't mean each city is a religion.
- youtube.com/watch?v=OmDaUO61jhA - Genetically Modified Skeptic - Is atheism a cult?