It is called scapegoating.
But, suppose, for the sake of argument that religion is evil, and also man made. What would that say about religion's inventors?
The truth is that people do not need God to do evil. People do evil for control, wealth and sex. If anything, religion restrains peoples' darker desires by giving people moral guidelines. And, Christianity, at least, says that murderers go to Hell, not to Heaven. Perhaps you don't like the idea of being threatened with Hell to do good, but it sure is not an incentive to do evil.