Muslims believe Sharia law to be the perfect law as dictated by god. They believe that muslims shall reside under sharia in jannat (heaven. Sharia law is derived from the qur'an and from Muhammad's saying in the hadiths, sunnahs, and sirat. There are some disagreements about certain minor aspects of Sharia within the muslim community.
Sharia law controls almost every aspect of muslims lives. it also regulates those non-believers(dhimmi's who live in Islamic states. Sharia does not allow freedom of speech in such matters as criticism of Muhammad, the Qur'an and Islam on the whole. Such criticism is blasphemy and punishable by death. Sharia law also punishes apostasy with death.