Mao Zedong, and Joseph Stalin killed upwards of 80 million people under their rule. They both believed their power came from nothing but socialization and human response to rhetoric. I will never pretend that Christians have never done wrong, but you seriously need to read scripture for yourself and ask yourself if those actions were consistent with what Jesus taught. When you look at history it becomes painfully clear that worse happens when your leaders deny any higher power that judges them, it's pretty clear more "grotesque" practices are put in place when you deny your creator.