Most Libyans adhere to the Sunni branch of Islam, which provides both a spiritual guide for individuals and a keystone for government policy. Its tenets stress a unity of religion and state rather than a separation or distinction between the two, and even those Muslims who have ceased to believe fully in Islam retain Islamic habits and attitudes. The post-revolution National Transitional Council has explicitly endeavored to reaffirm Islamic values, enhance appreciation of Islamic culture, elevate the status of Qur'anic law and, to a considerable degree, emphasize Qur'anic practice in everyday Libyan life with legal implementation in accordance to Islamic jurisprudence known as sharia. Libya has a small presence of Ahmadis and Shias consisting of Pakistani immigrants, though unrecongnized by the state .
During the seventh century, Muslims, who were spreading their faith, reached Libya to spread the message. The urban centers soon became substantially Islamic, but widespread conversion of the nomads of the desert did not come until after large-scale invasions in the eleventh century by Bedouin tribes from Arabia and Egypt.
A residue of pre-Islamic beliefs blended with the Islam of the Arabs. Hence, popular Islam became an overlay of Quranic ritual and principles upon the vestiges of earlier beliefs—prevalent throughout North Africa—in jinns (spirits), the evil eye, rites to ensure good fortune, and cult veneration of local saints. The educated of the cities and towns served as the primary bearers and of the more austere brand of orthodox Islam.