The predominant religion in Sudan is Islam, practised by around 97% of the total population. Christianity is the second largest religion in the country, accounting for around 2.2% of the population. A minority of Sudanese adhere to indigenous beliefs, primarily in the Nuba Mountains . Prior to the arrival of Islam and Christianity, the polytheistic Kushite religion was the dominant faith in ancient Nubia, part of modern-day Sudan. Lasting until the fourth century CE, the Kushite religion featured a pantheon of local deities such as Apedemak and some ancient Egyptian deities, including Amun.

Between the fifth to twelve centuries, the medieval Christian kingdoms of Nubia controlled present-day Sudan and delayed the expansion of Islam through a peace and trade treaty, known as the Baqt, with the ruling Muslim power in Cairo. Following the fall of the Christian kingdoms in the sixteenth century, Islam spread to Nubia peacefully when Muslim Kenzi preachers and merchants intermarried with Christian Danagla. In 1504, the native Funj Sultanate would be the first Muslim polity established in the region, attracting Sufi scholars and religious teachers from Egypt and the Hejaz. By the seventeenth century, western Sudan would come under the Islamic rule of the Sultanate of Darfur, another indigenous state.

The religious composition of northern Sudan would gradually shift from Coptic Christianity and traditional religions to Islam, with numerous indigenous groups such as the Nubians, Beja, Nuba, Fur, and Zaghawa largely converting to Islam over time. In the 1800s, both the Funj and Darfur Sultanates would collapse in the wake of Turco-Egyptian invasions. The early nineteenth century also saw the immigration of many Egyptian Copts to the country, and despite initially facing tolerant treatment, were persecuted by the Mahdist State by the end of that century.Minority Rights Group International, World Directory of Minorities and Indigenous Peoples - Sudan : Copts, 2008, available at: http://www.unhcr.org/refworld/docid/49749ca6c.html [accessed 21 December 2010] "Emigration from Egypt peaked in the early nineteenth century and the generally tolerant reception they received in Sudan was interrupted by a decade of persecution under Mahdist rule at the end that century. Many were obliged to relinquish their faith and adopted Islam, intermarrying with other Sudanese. The Anglo-Egyptian invasion in 1898 allowed Copts greater religious and economic freedom" A variety of Christian denominations would be introduced to the Nuba Mountains and southern Sudan during the colonial era.

In 2020, the Sudanese transitional government signed an accord with the political and armed group Sudan People's Liberation Movement–North (SPLM–N), which officially separated religion and the state.

Islam

Up until 2010 (before the secession of South Sudan in 2011), the country was 80% Muslim; as of 2015, the proportion grew to 97%. Most Sudanese Muslims are adherents of the Sunni branch of Islam, with the vast majority following the Maliki school, although Shafi'i and Hanafi schools are also present.

Sunni Islam in Sudan is not marked by a uniform body of belief and practice, however. Some Muslims opposed aspects of Sunni orthodoxy, and rites having a non-Islamic origin were widespread, being accepted as if they were integral to Islam, or sometimes being recognized as separate. A great majority of Muslims in Sudan adhere to Sufism or are heavily influenced by it, making Sudan one of the most tolerant Muslim majority countries in the world.

Five pillars

Sunni Islam requires of the faithful five fundamental obligations that constitute the Five Pillars of Islam. The first pillar, the shahadah or profession of faith is the affirmation "There is no deity but God, and Muhammad is His messenger." It is the first step in becoming a Muslim. The second obligation is prayer at five specified times of the day. The third enjoins almsgiving. The fourth requires fasting during daylight hours in the month of Ramadan. The fifth requires a pilgrimage to Mecca for those able to perform it, to participate in the special rites that occur during the twelfth month of the lunar calendar.

Most Sudanese Muslims are born to the faith and meet the first requirement. Many males in the cities and larger towns manage to pray five times a day: at dawn, noon, mid afternoon, sundown, and evening. The well-to-do perform little work during Ramadan, and many businesses close or operate on reduced schedules. In the early 1990s, its observance appeared to be widespread, especially in urban areas and among sedentary Sudanese Muslims.

The pilgrimage to Mecca is less costly and arduous for the Sudanese than it is for many Muslims. Nevertheless, it takes time (or money if travel is by air), and the ordinary Sudanese Muslim has generally found it difficult to accomplish, rarely undertaking it before middle age. Some have joined pilgrimage societies into which members pay a small amount monthly and choose one of their number when sufficient funds have accumulated to send someone on the pilgrimage. A returned pilgrim is entitled to use the honorific title hajj or hajjih for a woman.

Another ceremony commonly observed is the great feast Id al Adha (also known as Id al Kabir), representing the sacrifice made during the last days of the pilgrimage. The centerpiece of the day is the slaughter of a sheep, which is distributed to the poor, kin, neighbors, and friends, as well as the immediate family.

Islam imposes a standard of conduct encouraging generosity, fairness, and honesty towards other Muslims. Sudanese Arabs, especially those who are wealthy, are expected by their coreligionists to be generous.

Islam in Sudanese law In accordance with Islamic law Sudanese Muslims do not eat pork nor do they consume alcohol. Usury is also forbidden by Islamic law, but Islamic banks have developed other ways of making money available to the public.

In Sudan (until 1983) modern criminal and civil, including commercial, law generally prevailed. In the north, however, the sharia was expected to govern what is usually called family and personal law, i.e., matters such as marriage, divorce, and inheritance. In the towns and in some sedentary communities sharia was accepted, but in other sedentary communities and among nomads local custom was likely to prevailparticularly with respect to inheritance.

In September 1983, Nimeiri imposed the sharia throughout the land, eliminating the civil and penal codes by which the country had been governed in the twentieth century. Traditional Islamic punishments were imposed for theft, adultery, homicide, and other crimes. The zealousness with which these punishments were carried out contributed to the fall of Nimeiri. Minority rights are severely restricted under Sharia.

In July 2020, a number of these laws were repealed, including the one that had provided for the death sentence for apostasy,Sheen, J. (1997). Freedom of Religion and Belief: A World Report. Routledge, p. 76. the renouncement of Islam by a Muslim.

Other influences Islam is a monotheistic religion and insists that there can be no intercessors between an individual and God. Nevertheless, Sudanese Islam includes a belief in spirits as sources of illness or other afflictions and in magical ways of dealing with them. The imam of a mosque is a prayer leader and preacher of sermons. He may also be a teacher and in smaller communities combines both functions. In the latter role, he is called a faqih (pl., fuqaha), although a faqih need not be an imam. In addition to teaching in the local Qur'anic school (khalwa), the faqih is expected to write texts (from the Qur'an) or magical verses to be used as amulets and cures. His blessing may be asked at births, marriages, deaths, and other important occasions, and he may participate in wholly non-Islamic harvest rites in some remote places. All of these functions and capacities make the faqih the most important figure in popular Islam. But he is not a priest. His religious authority is based on his putative knowledge of the Qur'an, the sharia, and techniques for dealing with occult threats to health and well-being. The notion that the words of the Qur'an will protect against the actions of evil spirits or the evil eye is deeply embedded in popular Islam, and the amulets prepared by the faqih are intended to protect their wearers against these dangers.

In Sudan as in much of African Islam, the cult of the saint is of considerable importance, although some Muslims would reject it. The development of the cult is closely related to the presence of the religious orders; many who came to be considered saints on their deaths were founders or leaders of religious orders who in their lifetimes were thought to have barakah, a state of blessedness implying a spiritual power inherent in the religious office. Baraka intensifies after death as the deceased becomes a wali (literally friend of God, but in this context translated as saint). The tomb and other places associated with the saintly being become the loci of the person's baraka, and in some views he or she becomes the guardian spirit of the locality. The intercession of the wali is sought on a variety of occasions, particularly by those seeking cures or by barren women desiring children. A saint's annual holy day is the occasion of a local festival that may attract a large gathering.

Better-educated Muslims in Sudan may participate in prayer at a saint's tomb but argue that prayer is directed only to God. Many others, however, see the saint not merely as an intercessor with and an agent of God, but also as a nearly autonomous source of blessing and power, thereby approaching "popular" as opposed to orthodox Islam.

Movements and religious orders Islam made its deepest and longest lasting impact in Sudan through the activity of the Islamic religious brotherhoods or orders. These orders emerged in the Middle East in the twelfth century in connection with the development of Sufism, a reaction based in mysticism to the strongly legalistic orientation of mainstream Islam. These orders first came to Sudan in the sixteenth century and became significant in the eighteenth. Sufism seeks its adherents a closer personal relationship with God through special spiritual disciplines. The exercises (or dhikr) include reciting prayers and passages of the Qur'an and repeating the names, or attributes, of God while performing physical movements according to the formula established by the founder of the particular order. Singing and dancing may be introduced. The outcome of an exercise, which lasts much longer than the usual daily prayer, is often a state of ecstatic abandon.

A mystical or devotional way (sing. tariqa; pl. turuq) is the basis for the formation of particular orders, each of which is also called a tariqa. The specialists in religious law and learning initially looked askance at Sufism and the Sufi orders, but the leaders of Sufi orders in Sudan have won acceptance by acknowledging the significance of the sharia and not claiming that Sufism replaces it.

The principal turuq varies considerably in their practice and internal organization. Some orders are tightly organized in a hierarchical fashion; others have allowed their local branches considerable autonomy. There may be as many as a dozen Turuq in Sudan. Some are restricted to that country; others are widespread in Africa or the Middle East. Several Turuq, for all practical purposes independent, are offshoots of older orders and were established by men who altered in major or minor ways the tariqa of the orders to which they had formerly been attached.