I think about how mighty and powerful those muslim murderers must have been feeling as they killed a fellow human being in the name of their religious zealotry. And I think that's really what all of this is about: the rush of power and righteousness the zealot feels when he imagines that he is an extension of God, with the power over life and death.
And then I think of all the times I've heard Christians calling for the execution of people they consider to be the enemies of God, and I realize that it's all the same. It's not really about God at all. It's about their own egos, and their lust for that feeling of righteousness and power at the expense of anything else. And how that lust can become so strong that they even become willing to commit murder, to satiate it.
But, of course, it can't be satiated for long. Almost immediately after, they will want to feel it again.