Sufism is a mystical branch of Islam. Though many Shia and Sunni Muslims reject Sufis as true Muslims, Sufi Muslims consider themselves followers of Allah. Further, Sufis believe they are practicing the highest form of worship or devotion. Strongly emphasizing peace and non-violence, Sufis have sometimes received great persecution from other Muslim groups. Further, since Sufism represents only about one percent of Islam worldwide, it has often been seen as less important, despite its rich history and significant impact on culture.