Quote from MarketMasher:
When reading the article of people who knew the older brother, he was described as "cocky" and a "man-of-the-house" type (i.e. - arrogant). It reminded me of the interview of a Florida pilot who met the 9-11 hijacker and described him the same way - an arrogant, in-your-face type.
These are people who are egotists. They have some belief that they are better than others and will use whatever rationale they can to self-elevate themselves. In these cases, religion is their tool for self-aggrandizement and self-delusion. If not religion, it would be something else (birthright, whatever...)
Think of it - they are, in their own delusion, saying "God wants these people dead, but He can't do it Himself, so I'm going to have to do it for Him."
Arrogant to the point of Blasphemous - they elevate themselves into being their own version of God because, in their own view, God can't handle it.
Make that Arrogant AND Ignorant....
You're describing a psychopath.