Same source etc, but different religions ?

[CapnAwesome]

Well early Christians weren't really differentiated from the Jews. They were considered a sect of Judaism until the religion started getting significant Gentile converts. Muhammad traveled a lot and obvious had exposure to the bible and most of the Qu'ran reads like a poorly remembered rendition of the bible. So it's obviously based largely on a mixture of Christianity, Middle Eastern morality and Muhammad's personal ethics. Not a huge mystery. Were you expecting some supernatural reason?