Islam has killed in 270 million people in the 1400 it came into being. It is as much as a political system as religious. Maybe more so. Islam has put more people into slavery then Judism and Christianity combined. Kafir is not merely a unbeliever, it is one at the same lever as a dog.
After Allah, a moon god, Mohammad is the central figure of Islam. His life reads like a who's who of murder, deceit, lies, racism, rants, power, greed and genocide.
Satan is probably the motivator behind Islam. Gabriel was not the one who came to him in a dream and vision, it was satan.