What is the difference between atheism and fascism?

Its really starting to irritate me that atheist are generally convinced that there culture is superior to all other cultures and beliefs. Before you go uming I'm a Christian, I'm not. I'm just disgusted with the attitude of intolerance atheist have displayed, and yet they point the finger at Christianity, and frankly I am here in defense of all religions. Why do atheist think its ok to act like pricks? Sometimes they claim they do it because they are tired of christian persecution, which I've yet to see, or tired of being forced into conversion. Has fighting fire with fire worked for you? What is your excuse for your asinine behavior?