Because he can? Because Allah is great? Because getting others to eliminate people he sees as 'the problem' or 'Infidels' without getting his hands dirty (or blowed up) makes him powerful and better than someone who doesn't believe?

People need rules. Desperately. IMO, religion came along as a way to get people to obey rules when the ones being ruled said "Why should we obey you? You're just a man!", so someone who's super-human in every way- all powerful, all-knowing, omni-present, was needed.

How can three religions that have common basis be so unable to coexist?