honeybutterflies
Atheist means person with no religion. Not believing in anything can't be religion.
Actually what you are describing is Agnostic.
I got some great pseudo religious cults for you... since we all love the nuts of the bunch!
There is the Peoples Temple with Jim Jones. He moved all those people out to South America, away from their families, and essentially controlled them to death.
The ever famous Heaven's Gate, who their leader Marshall Applewhite had convinced everyone to leave their corporeal bodies to ascend to heaven riding on a UFO behind the comet Hale Bopp. They poisoned themselves, forever cementing their history as a suicide cult. But the manner in which they were discovered was strange, in their San Deigo Compound they were all found wearing Nike tennis shoes, black jumpsuits, with purple cloths draped over them, neatly laid down.
And then there is the Japanese terrorist cult Aum Shinrikyo. Their blend of extremist and apocalyptic ideas lead to their members conducting a Sarin Gas attack on a Tokyo Subway.
All these groups took their religious views a little to far, even to the extent of committing murder.
But this pales in comparison to the Spanish Inquisition, The Crusades, the witch hunts and countless other wars waged in the name of "God."
My favorite quote about Religion was from the father of communism, Karl Marx."Religion is the Opiate of the Masses."