Muhammad himself was convinced that the "revelations" he received in the Hira Cave were evil, and from a demon (Jinn). 

 Muhammad's constant fits, foaming at the mouth and other manifestations certainly fit in with that idea. This is how demon possessed people are known to behave today, as they did in both the times of Jesus and Muhammad. The Hebrew prophets, and Jesus Christ never behaved like this. But all over the world where demons are listened to, you will find this kind of behavior.

Murder, rape, plunder and destruction are all perfectly fine with Allah - if done in the name of Islam

Koran (Qur'an) 8:67-68