In the United States the state determines what is legal and illegal. This is a common sense approach to prevent individuals from acting out of personal principles that they or this or that group believes but some other individuals or groups don't believe. In this way Jews don't run around killing folk who eat pork and Christians don't get to kill folk who disagree with their notions of when life begins. Without this we would all be on somebody's hit list. But belief is a powerful thing and causes common sense to fly out the window.
Murder, for a Christian, for example, is a real big no no, so folk who murder others put them in a camp that should be murdered. This is the logic of belief, kill killers and give yourself a pass because killing killer while killing, makes it a bit easier to justify for the insane. Even the state practices this form of imbecility providing more justification.
The evil of hate is what religion is supposed to cure but hate is tricky. Hate always infects a religion from the inside calling itself the good. God says only I judge, but Christians won't listen to Him.