When The Answer Stares You in the Face

"To most of us nothing is so invisible as an unpleasant truth. Though it is held before our eyes, pushed under our noses, rammed down our throats- we know it not." Eric Hoffer

Now, Brother, are you trying to understand your brother-- or are you trying to understand why Islam has made your brother into a raving murder promoting fanatic? It's simple, if you but look: Islam is an absolutist ideology that openly justifies and employs terror, and violence in general, to destroy its enemies and cow the rest. Your brother is one of those many sad sack souls that desperately seeks to find meaning in whatever absolutist ideology seems the strong horse of the day; and on this day it is Islam.
Nothing else.