In the name of anything, anything bad happens. Human nature, and the precarious nature of survival has created conditions of vulnerability, and the possible conditions for evil if so chosen.
Evil comes in any form be it theist, or atheist. The vehicle of religion, or anti religion is used maliciously for personal gain and power.
To me religion is a form of blindness to reality when it pits believer vs. non believer. I personally am unwilling to die for the sake of myths myself. But evil is something chosen without any regard for other life. It will use anything to get its way.
Disillusionment, and delusions are also dangerous roads as well. While not outrightly evil there are traps of perception that cause much harm. Error is as dangerous as evil imo.
If Christianity is not reality then it is blind to much good and thus it is bad stuff. Christianity is error for sincere people, and it also invites much evil in its abuse's.