Its hard, atheists generally don't care and won't try to convert anyone. But every religion created by man is about spreading the message to the heathens. If you're Christian you simply cannot accept atheism.
I'm not even sure if most religions are like that. Christianity and Islam seem to, and the Krishna Consciousness people, and the Scientologists, but Judaism and polytheists mostly don't. Haven't seen much Buddhist proselytizing either. It varies.
Dawkins and Harris and the other New Atheists certainly try to spread their atheism though.