Sufism is the major expression of mysticism in Islam. While Sufism developed out of the fusion of Qur’anic ascetic tendencies and the vast fund of Christian (and other) mystical sayings present throughout the classical world, by approximately the 10th century it had become a uniquely Islamic feature. Major writers such as al-Ghazali and Ibn al-ʿArabi took this heritage and molded it both into a normative tradition for Islam as a whole (by wedding it to the Prophet Muhammad’s life experience) and, in the case of Ibn al-ʿArabi, into completely new spiritual paths. These interpretations of mysticism were critical in the vast conversion to Islam that happened during the period 1000–1800. Although other factors were involved as well, including trading by Muslims and the Islamic educational system, this conversion happened largely at the hands of the Sufis, especially holy men and healers, and thus the Muslim world is still largely Sufi or Sufi-influenced. Starting in the 19th century, however, and culminating in the mid-20th century, large numbers of Muslims abandoned Sufism, accusing it of being fundamentally anti-Islamic and even polytheistic. Today although Sufis still constitute the bulk of world Muslims, and they are visible throughout the non-Muslim world as well, their belief system is under attack as never before.
Mysticism in Islam is understood in terms of a process (tariq) that is guided by the direction of a spiritual mentor (called a shaykh or a pir) having the goal of eventual union
with God (Allah). This process is usually a life-long one, during the course of which it is crucial that the initiate combat his or her baser impulses located in the soul (Qur’an 12:53). To complete this process, the initiate must place himself or herself completely under the spiritual supervision of the mentor and carry out an ever-increasing series of spiritual (and sometimes physical) exercises. These exercises have the goal of emptying out the personality of the initiate and filling it with the remembrance of the divine and, ultimately, preparing the person for union. Additional exercises can include mortification of the body and deprivation of sleep and food, but interestingly not chastity, which is not seen as a value by Muslims. The initiate proceeds through a series of levels or stations that progress toward the promised union. Sufism as a religious development is unique to Islam as a system, but it is in itself a system that can be translated into other beliefs (Christianity, Judaism, and Hinduism) as well, and it has demonstrated a remarkable adaptability through the centuries.
From a very early period an ascetic strain emerged within Islam. While it is difficult to say whether the Prophet Muhammad (c. 570–632) was personally ascetic—as his character has been shaped in the stories about him to both the advantage of asceticism and against it—one finds a minority of his Companions (sahaba) who lived an ascetic lifestyle. This tendency stood in sharp contrast to the luxurious and wealthy lifestyles affected by many Muslims during the early period, especially in the wake of the great Islamic conquests (634–732) during the course of which the area of the eastern Mediterranean Basin and the Iranian Plateau came to be controlled by Muslims. While these conquests brought immense wealth to an elite, individuals could always be found who abstained completely from partaking in this wealth. Early Asceticism and Sufism In the process of abstaining, these Muslim ascetics, the best known of whom are Abu al- Darda’ (d. 651) and Abu Dharr al-Ghifari (d. 652), followed closely in the ascetic practices of the Christian monastics around them (and later, when in Central Asia, the example of Buddhism monks and, in India, Hindu yogis). For centuries Christian monks in the regions of Syria and Egypt had practiced very severe forms of bodily mortification and deprivation, and for these pains had acquired for themselves a high level of local social and religious prestige. In the words of Peter Brown, they had become the local holy men, looked to by the population for arbitration and miracles, and they were feared by the secular and ecclesiastical hierarchies, respectively.1 This social and religious prestige is reflected in the Qur’an, where it is said “and you will find that the closest in affection to the believers those who say ‘we are Christians.’ For among them are priests and monks and they are not arrogant” (5:82).2 Muhammad himself is said to have been close to a certain monk by the name of Bahira (or Sergius).
However, Muslim asceticism, while maintaining deprivation, did not embrace all of the elements of Christian monasticism. From a very early stage, as noted above, the chastity characteristic of monks and nuns was rejected (although some early examples do exist of Muslims castrating themselves), and the complete withdrawal from society of the anchorite lifestyle was also not accepted. Otherwise, what came to be called zuhd (asceticism) during the 7th, 8th, and 9th centuries became a popular lifestyle of a certain segment of Muslims. Even for those for whom it was not an actual lifestyle, zuhd constituted an ideal, a criterion by which to judge oneself.
David Cook (Oxford Research Encyclopedia of Religion)