Muhammad justified his crimes with divine revelation:

The details of all his criminal onslaughts in the form of battles and assassinations are chronicled in this article in a chronological manner. One should note that every time the 'Apostle of Peace' committed one of his criminal onslaughts, he always justified the crimes by quickly claiming a 'divine revelation' which conveniently removed the blame from his bloodied hands.

Muhammad was married to a 6 year old Jewish girl, while he was 51, and he had 11 wives

 Islamic fundamentalism promotes jihad (holy war), against those of other religious and political views.