I'm an atheist. I was not always so. I was born and raised a Christian. It took me 28 years to lose my religion, it did not happen overnight. I'm sure most of you share the same story. We were in the same situation that believers are now. They have not been able to come to the truth that we have come to. Don't condemn your fellow man for being as we once were. Condemn Christianity, not the Christian. Condemn Islam, not the Muslim. Condemn Jewdaism, not the Jew.
We are all men, brothers in humanity. Feel for those lost to the truth. Love and kindness is why our sources has survived this long.