I find it interesting that theists who do evil things in the name of their god are considered to be sinners and not really doing what their god wants. How do you know what their god wants? How can you know that their god is not speaking to them and actually telling them what to do? Just because it offends you?
That's the great fallacy of religions. Once you accept the concept of a supernatural being who controls the universe and who can do anything He wishes, you can no longer claim that someone else is not doing His bidding. What that person does may be offensive to you, but how can you know that you are right and he is wrong? Maybe God DID tell him to do those things. After all, God did tell Joshua, on more than one occasion, to kill all the inhabitants of towns he conquered, down to the last man, woman, child and cow! Who's to say that God wouldn't tell someone to kill an abortion doctor, or a gay man, or anyone else, for that matter. I know, you don't want to believe that God would do such a thing, but HOW-CAN-YOU-KNOW?