At The Richard Dawkins Foundation For Reason and Science you can find a witty and urbane video of TV host and comedian Bill Maher. In the video Maher is primarily arguing that “atheism is not a religion.” Maher contrasts the difference between atheism and religion like this:
When it comes to religion, we’re not two sides of the same coin, and you don’t get to put your unreason upon the same shelf as my reason. Your stuff [religion] has to go over there, on the shelf with Zeus, and Thor, and the crackin’. With the stuff that is not evidence based, stuff that religious people never change their mind about, no matter what happens.
What keeps atheism from being a religion? Because atheism is based on reason, but religion is based on faith and lacks evidence.