Sharia law is a set of religious rules that every Islamic believer must adhere to and it refers to the regulation of interpersonal relations. The main source of this right is the holy book of Muslims, the Qur'an, followed by the Sunnah, Ijma ul-um'et, Kiyas, Adet and Er-rei. In addition to Sharia law, there is a canon law that refers to the internal organization of Islamic states and is passed by the ruler. The main characteristics of this right are perfection, universality and sacredness. It is designed in a way that can be adapted to both Muslims and non-Muslims. Also, some of the curiosities of the religion itself are presented, such as the relationship between a man and a woman or marriage, the position of women, types of punishment, homosexuality and the Islamic calendar. Islamic extremists have the ideal of creating a single Islamic state and thus spreading their faith to the whole world. It is this ideal that still creates wars in the Middle East and many innocent victims, which they justify with a "greater goal". Nigeria is today one of the countries that contains Sharia law in its legal order. This fact creates a large proportion between Muslims and non-Muslims in that country because coexistence seems impossible.