Almost all of the people of Pakistan are Muslims or at least follow Islamic traditions, and Islamic ideals and practices suffuse virtually all parts of Pakistani life. Most Pakistanis belong to the Sunni sect, the major branch of Islam. There are also significant numbers of Shiʿi Muslims. Among Sunnis, Sufism is extremely popular and influential. In addition to the two main groups there is a very small sect called the Aḥmadiyyah, which is also sometimes called the Qadiani (for Qadian, India, where the sect originated).

The role of religion in Pakistani society and politics finds its most visible expression in the Islamic Assembly (Jamāʿat-i Islāmī) party. Founded in 1941 by Abū al-Aʿlā Mawdūdī (Maududi), one of the world’s foremost thinkers in Sunni revivalism, the party has long played a role in Pakistan’s political life and has continually advocated refashioning Pakistan as a chaste Islamic or theocratic state.

The majority of Pakistani Sunnis belong to the Ḥanafiyyah (Hanafite) school, which is one of four major schools (madhhabs) or subsects of Islamic jurisprudence; it is perhaps the most liberal of the four but nevertheless is still demanding in its instructions to the faithful. Two popular reform movements founded in northern India—the Deoband and Barelwi schools—are likewise widespread in Pakistan. Differences between the two movements over a variety of theological issues are significant to the point that violence often has erupted between them. Another group, Tablīghī Jamāʿat (founded 1926), headquartered in Raiwind, near Lahore, is a lay ministry group whose annual conference attracts hundreds of thousands of members from throughout the world. It is perhaps the largest grassroots Muslim organization in the world.

The Wahhābī movement, founded in Arabia, has made inroads in Pakistan, most notably among the tribal Pashtuns in the Afghan border areas. Moreover, after the Soviet invasion of Afghanistan in 1979, Saudi Arabia assisted Pakistan in caring for vast numbers of Afghan refugees in the border areas and in the construction and staffing of thousands of traditional Sunni madrasahs (religious schools). Those schools generally provided instruction along Wahhābī lines, and they subsequently became vehicles for the spreading influence of extremist groups (particularly al-Qaeda and the Taliban of Afghanistan) in Balochistan, Khyber Pakhtunkhwa, and elsewhere throughout the country. Although extremism in the name of Islam has become more pronounced in Pakistan since 2000, more-moderate Sunni Muslims are found in the country’s business community, especially among Gujarati Memons and Chiniotis from Punjab who follow less-conservative Islamic traditions.

Among the Shiʿah there are several subsects; notable are the Ismāʿīlīs (or Seveners)—including the Nizārīs (followers of the Aga Khans, among whom are the Khojas and the Bohrās), who are prominent in commerce and industry—and the Ithnā ʿAshariyyah (or Twelvers), who are more austere in their practices and more closely resemble the Shiʿi tradition found in Iran. Shiʿis have long been the target of Sunni radicals, and violent encounters between followers of the two sects are common.

With the exception of some sects, such as Dawoodi Bohrās, there is no concept of an ordained priesthood among Pakistan’s Muslims. Anyone who leads prayers in mosques may be appointed imam. Those who are formally trained in religion are accorded the honorific mullah or mawlānā. Collectively, the community of Muslim scholars is known as the ʿulamāʾ (“scholars”), but among the practitioners of a more popular sect of Islam (generally associated with Sufism) there are powerful hereditary networks of holy men called pīrs, who receive great reverence (as well as gifts in cash or kind) from a multitude of followers. An established pīr may pass on his spiritual powers and sanctified authority to one or more of his murīds (“disciples”), who may then operate as pīrs in their own right. There are also many self-appointed pīrs who practice locally without being properly inducted into one of the major Sufi orders. Pīrs who occupy high positions in the pīr hierarchy wield great power and play an influential role in public affairs.

Among the basic tenets of the Aḥmadiyyah is the belief that other prophets came after Muhammad and that their leader, the 19th century’s Mīrzā Ghulām Aḥmad, was called to accept a divine mission. The Aḥmadiyyah therefore appear to question Muhammad’s role as the last of God’s prophets. More conservative Muslims find this seeming revision of traditional belief blasphemous, and in 1974 a constitutional amendment declared the Aḥmadiyyah community to be non-Muslims. The community became the focal point of riots in the Punjab in 1953, instigated by the Islamic Assembly but also including a broad representation of religious groups. Since then the Aḥmadiyyah have experienced considerable persecution, particularly during the administration (1977–88) of Gen. Mohammad Zia-ul-Haq—when they were denied all semblance of Islamic character—and they have been denied positions in the civil service and the military and often have been forced to conceal their identity.

At the time of partition, most Hindus left newly formed West Pakistan for India. In the east, wealthier Hindus also fled newly formed East Pakistan, but a sizeable minority of Hindus (nearly 10 million) stayed behind. The vast majority remained there until the civil war of 1971 (which led to the creation of Bangladesh) compelled them to seek refuge in India.

There is also a small but fairly significant population of Christians in the country. There are adherents to a variety of denominations, Roman Catholicism being the largest. Violent attacks against Christians became increasingly common during the Zia-ul-Haq regime, a trend that continued afterward with the increase of religious strife.

Settlement patterns

Geographically, the population of Pakistan is distributed rather unevenly. More than half of the population is in Punjab; on the other hand, Balochistan, the largest province in terms of area, has significant areas with virtually no settled population. Likewise, within each province, the population further pools in various areas. Much of the population of Balochistan, for instance, is concentrated in the area of Quetta. The region around Karachi and the inhabited strip along the Indus River are the most densely settled areas in Sindh province. Within Punjab the population density generally decreases from northeast to southwest. In Khyber Pakhtunkhwa the plain around Peshawar and Mardan is a high-density area. Broadly speaking, population density is greatest in fertile agricultural areas. Nomadism and transhumance, once common lifestyles in Pakistan, are practiced by relatively few people in the 21st century.