Very similar was the teaching of Abu Yazid or Bayazid of Bistam (d. 260), who was also of Zoroastrian descent. The pantheistic element is very clearly defined: “God,” he said, “is an unfathomable ocean”; he himself was the throne of God, the preserved Tablet, the Pen, the Word--all images taken from the Qur´an--Abraham, Moses, Jesus, and Gabriel, for all who obtain true being are absorbed into God and become one with God.
Pantheistic views and the doctrine of _hulul_ occur frequently in Sufi teaching, but they are by no means universal. Indeed, we cannot make any accurate statement of Sufi doctrine in detail, but only of general principles and tendencies. The Sufis do not form a sect, but are simply devotees of mystical tendencies spread through all the branches of the Muslim community. In the 3rd cent. they are most prominent amongst the Shi`ites, and so Shi`ite views seem to be incorporated in Sufism, but they form no integral part of it. Precisely similar conditions occur in Christianity where mysticism has flourished in the extremer Protestant sects as well as in the contemplative orders of the Catholic Church, and, in spite of theological differences, has a very considerable amount of common material. Only it must be noted that no basis of mysticism exists unless some such relations between the human soul and God are pre-supposed, as are suggested by neo-Platonism. Christian mysticism, in the true sense, does not begin in the West until the works of the Pseudo-Dionysius were translated into Latin in the 9th cent. A.D., and Muslim mysticism dates from the translation of the _Theology of Aristotle_. On the other hand, it must also be noted that mysticism exercises a strong modifying influence on theology generally. The tendency of mysticism is towards a latitudinarian type: it is consequently opposed, consciously or unconsciously, to definite dogmatic teaching and so to speculative theology and philosophy.
Superficially Muslim mysticism seems to be organised like a sect. Reference is often made to the various “grades” of Sufis. But these are not official grades like those of the Isma`ilians and similar bodies, but denote successive stages on the path of personal holiness: it is no more than a fanciful terminology, perhaps borrowed from some of the sects because it seems that Sufism flourished earliest and most freely in some of the extremer Shi`ite groups. It was, and is, most usual for the beginner in the path of holiness to put himself under the direction of some experienced spiritual guide, who acts as his teacher, and is known as _sheikh_, _murshid_, or _pir_. In many cases this pupilage involves absolute and blind obedience to the teacher, because the renunciation of personal wishes and inclinations and all that can be described as self-will is one of the forms of abnegation required of those who seek to be weaned from earthly interests. From the grouping of devotees around some prominent teacher has arisen the foundation of darwish confraternities, sometimes as sodalities of laymen, who pursue their secular occupations and meet from time to time for religious exercises and instruction, and sometimes as permanent communities living in strict obedience under a sheikh. Traces of such monastic institutions appear in Damascus about 150 A.H., and in Khurasan some fifty years later. None of the existing orders of Islam, however, seem to be of so early a date. We hear of a sheikh Alwan (circ. 149), whose shrine is at Jedda, and who is the reputed founder of the Alwaniya community, a body now existing only as a subdivision of the Rifa`ite order. There are also orders known as the _Adhamiya_, _Bastamiya_, and _Saqatiya_, which trace their origin to Ibrahim b. Adham (cf. above), to Bayazid Bastami, and to Sari as-Saqati respectively, but whose real origin is uncertain.