When did Sharia law come along? Is it in the Koran? Is it practiced by all muslims? Isn’t it true that our real enemies are the adherents to Sharia Law? Who wrote the Koran?
The Hadith ( which is different from the Koran; it is just "holy" words that Mohammed spoke...supposedly ) is where Sharia Law comes from. Unlike the Ten Commandments, which ALL Jews and Christians believe and try to live by, Sharia Law varies from Muslim community to community. The African Muslims perform "Pharonic circumcision" on girls; yet Arabs don't.
There are vastly different interpretations of what Sharia is. Unlike the Jewish law it's not specific and clear. Some parts (some of the most brutal and barbaric) are, but certainly not all. Over the centuries various Islamic scholars have interpreted it differently.
Because Islam sees Mohammed as the ideal man, his actions are to be emulated. Mohammed was a violent, abusive man who didn't deal with it very well when he didn't get what he wanted. Reframing his actions can only go so far.