Is atheism a religion if not why is it in religion and spirituality?

[Polly]

I just asked a questions to atheists and some answers were to post the question in religion and spirituality section. I don't think atheism is a religion like Christianity is a religion. Or is it? If it's not a religion why does it belong in religion and spirituality section?

[FrancescaDWard]

Atheism isn't a religion, but it pertains to the topic of religion. So it belongs there.

[MaryRWebb]

Atheism is being against religions, which, in a perspective is still a religion.