Religion does not have to be mystical or non-rational (no offense), religion by definition is a particular system of faith. Some atheist don't practice religion, yes. but other atheists like, well, me and the others, have our own religion... which in our case we prefer to have Science as our particular system of faith, so technically, some of us have a religion. so, going back to your question... the answer would be Scientism.
Another opinion:
Atheism isn't a religion by any means. There is no bible, no dogma, or rituals. And many Atheists will disagree on many things. The only identifier of being an Atheist, is the proclimation that they do not believe any god claims, especially without evidence.
I suppose some atheists might think they're a religion, but by definition it isn't. Religion requires "faith". Faith is acceptance of a concept without, or in spite of contrary, evidence.
Stalin was against religion and was strongly Atheist. He ran campaigns discouraging any form of religion.
He has no religion. He is atheist.
He is an atheist.
Atheist.
Atheist
his religion is christianity.
He was an Atheist, and therefore had no religion.
PewDiePie has not publicly disclosed his religious beliefs.
Matt Smith is an Atheist. Which means he does not have a religion and does not believe in a god(s) or supreme being.
Yes it is OK to go to church if you are an atheist. I am not sure what religion you are asking about -- the religion of the church or atheism
An Atheist.
She does not follow an organised religion but has also said that she is not an atheist.