Muslims promote Sharia law. Why do Christians not promote their law?

Muslims promote Sharia law. Why do Christians not promote their law?Some Muslim communities run with Sharia law. Other nations with a high Muslim population promote Sharia. It would seem from this phenomenon that Muslim law can be used to run a society as it does so in a few countries.I know of no country that uses Christian or biblical law and have not heard of any Christian effort to have their law accepted in their nation.This indicates that either Muslims are more religious than Christians, or Christians know that their laws would never be accepted as the law of the land.Meanwhile, the vast majority of nations have rejected both sets of religious laws for a more secular approach to law and governance.Briefly ---Which of these three sets of laws do you think are superior and why?Regards
DL