Defining religious violence, or don't forget to subtract

Hector Avalos writes:

According to my definition, if someone commits violence primarily because of a belief in supernatural forces and/or beings, then I count it as an act of religious violence. For example, if someone says: “God told me to kill gay people” then that counts as religious violence, especially as the person offers or evidences no other reason for killing gay people.

I am not sure about this definition, for various reasons. Persons highly motivated by an anti-supernaturalist world-view, who use violence to advance anti-supernaturalism, it seems to me, are engaged in religious violence. 

Further, the religious factor is hard to isolate in many cases. In the case of violence in Ireland, for example, the political factors and religious ones are hard to separate, and there I suspect the political factor is primary and the religious one is secondary. 

But let's take Avalos' definition and see where it gets us. It seems to me that if we are assessing the tendency of supernaturalism, or some particular version of it to produce violence, then to get a fair assessment, we have to introduce the category of religious nonviolence. Remember that one of the Ten Commandments is "Thou Shalt Not Kill." Now, most of us don't think that the Commandment is the only reason for not killing someone, but surely the disapproval of Almighty God provides a significant motive for those who believe that God exists not to commit certain acts of violence. 

By the way, I am not familiar with any cases of religiously motivated killings of gay people. The most famous case of gay-killing is Matthew Shepard, and in that case not only is there no evidence of a religious motivation, there is good reason to think that this was a case of drug-induced murder, not a gay-bashing. Maybe there are some, but I am not familiar with any.