The Sufi are considered by some as the inner or mystical dimension of Islam They are not considered a sect of Islam. A practitioner of this tradition is generally known as a Sūfī , though some senior members of the tradition reserve this term for those practitioners who have attained the goals of the Sufi tradition. Another common denomination is the word dervish. The word, ‘Sufi’ has been ascribed various origins, among them words meaning ‘purity’ and ‘wisdom.
Shi’ite beliefs had a lot of influence on Sufism, but mostly in the early days. One important idea which was transmitted from from the Shi’a to Sufism is that of the Mahdi (as), will come to save Muslims from corrupt worldly rulers.
Sufism is an esoteric doctrine transmitted by word of mouth, and sometimes, is is told, without even a spoken or written word, by an authorized teacher to a disciple, and from disciple to another disciple, in confidence. These secret instructions are acted upon by a disciple with perfect faith in the teacher. The disciple gives a report of his condition and experience in confidence to his teacher and receives another set of instructions most suitable to his state.