> Those who find their purpose in religion are very sad people indeed.
If only that were true! Most people who find their purpose in religion are very happy people because they are convinced that they are going to go to heaven or whatever equivalent after-life. And if they just got on with it and left the rest of us alone, no-one would bat an eyelid. It's when they decide that their religion is the only true religion and that other religions pose some sort of threat that the problems start.
This is particularly unfortunate when it comes to the three Abrahamic religions, where there are far more similarities than differences. E.g. most Western people are totally ignorant of the fact that Muslims believe in one God just like Christians and Jews, that they believe in Jesus, Adam and Eve, the Garden of Eden etc. Essentially, the one over-riding difference between Christianity, Judaism and Islam is that Muslims believe that Jesus was one of the most important prophets after Mohammed, Christians believe he was the son of God, and Jews don't believe either. That's a huge over-simplification, of course, but that's the synopsis.
However, all three religions employ fear as their main weapon. Telling someone that, if they commit sin, they will burn in the fire and brimstone of hell for all eternity can be very powerful against a weak mind.