There are more than 1 billion Muslims worldwide, fewer than one fifth of whom are Arab. Islam is the principal religion of much of Asia, including Indonesia (which has the world's largest Muslim population), Malaysia, Pakistan, Bangladesh, Afghanistan, Azerbaijan, Turkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, Kazakhstan, Iran, Iraq, Syria, Jordan, the Arabian Peninsula states, and Turkey. India also has one of the world's largest Muslim populations, although Islam is not the principal religion there. In Africa, Islam is the principal religion in Egypt, Algeria, Tunisia, Djibouti, Gambia, Guinea, Libya, Mali, Mauritania, Morocco, Niger, Senegal, Somalia, and Sudan, with sizable populations also in Chad, Eritrea, Ethiopia, Ghana, Tanzania (where the island of Zanzibar is predominantly Muslim), and Nigeria.
In Europe, Albania is predominantly Muslim, and, historically, Bulgaria, Bosnia, Macedonia, and Georgia have had Muslim populations. Elsewhere in Europe, significant immigrant communities of Muslims from N Africa, Turkey, and Asia exist in France, Germany, Great Britain, and other nations. In the Americas the Islamic population has substantially increased in recent years, both from conversions and the immigration of adherents from other parts of the world. In the United States, the number of Muslims has been variably estimated at 2-6 million; 20% of the population of Suriname is Muslim.
At the core of Islam is the Qur'an, believed to be the final revelation by a transcendent Allah [Arab.,=the God] to Muhammad, the Prophet of Islam; since the Divine Word was revealed in Arabic, this language is used in Islamic religious practice worldwide. Muslims believe in final reward and punishment, and the unity of the umma, the "nation" of Islam. Muslims submit to Allah through arkan ad-din, the five basic requirements or "pillars": shahadah, the affirmation that "there is no god but God, and Muhammad is the Messenger of God"; salah, the five daily ritual prayers (see liturgy, Islamic); zakat, the giving of alms, also known as a religious tax; Sawm, the dawn-to-sunset fast during the lunar month of Ramadan; and hajj, the pilgrimage to Mecca. The importance of the hajj can hardly be overestimated: this great annual pilgrimage unites Islam and its believers from around the world.
The ethos of Islam is in its attitude toward Allah: to His will Muslims submit; Him they praise and glorify; and in Him alone they hope. However, in popular or folk forms of Islam, Muslims ask intercession of the saints, prophets, and angels, while preserving the distinction between Creator and creature. Islam views the Message of Muhammad as the continuation and the fulfillment of a lineage of Prophecy that includes figures from the Hebrew Scriptures and the New Testament, notably Adam, Noah, Abraham, Moses, David, and Jesus. Islamic law reserves a communal entity status for the ahl al-kitab, People of the Book, i.e., those with revealed religions, including Jews and Christians. Islam also recognizes a number of extra-biblical prophets, such as Hud, Salih, Shuayb, and others of more obscure origin. The chief angels are Gabriel and Michael; devils are the evil jinn.
Other Islamic obligations include the duty to "commend good and reprimand evil," injunctions against usury and gambling, and prohibitions of alcohol and pork. Meat is permitted if the animal was ritually slaughtered; it is then called halal. Jihad, the exertion of efforts for the cause of God, is a duty satisfied at the communal and the individual level. At the individual level, it denotes the personal struggle to be righteous and follow the path ordained by God. Communally, it involves both encouraging what is good and correcting what is not and waging war to defend Islam.
In Islam, religion and social membership are inseparable: the ruler of the community (caliph; see caliphate) has both a religious and a political status. The unitary nature of Islam, as a system governing relations between a person and God, and a person and society, has contributed to the appeal and success of Islam.
The evolution of Islamic mysticism into organizational structures in the form of Sufi orders was, from the 13th cent. onwards, one of the driving forces in the spread of Islam (see Sufism; fakir). Sufi orders were instrumental in expanding the realm of Islam to trans-Saharan Africa, stabilizing its commercial and cultural links with the Mediterranean and the Middle East, and to SE Asia.
The original feasts of Islam are id al-fitr, corresponding to the breaking of the fast of Ramadan, and id al-adha, coinciding with the pilgrimage to Mecca. Shiite Islam also celebrates id al-ghadir, the anniversary of Muhammad's declaration of Ali as his successor. Other Islamic holidays include al-mawlid al-nabawwi, Muhammad's birthday, and al-isra wa-l-miraj, the anniversary of his miraculous journey to Jerusalem and ascension to Heaven. Among the Islamic religious honorifics are shaykh, a generic term refering to a religious scholar or a mystic master; qadi, a religious judge (handling particular cases); mufti, a religious authority who issues general legal opinions; and mullah, a synonym of shaykh used in the Persian-speaking world.
The revealed word of Islam, the Qur'an, in a formal Arabic which became more archaic with time, required explication. The Sunna, the spoken and acted example of the Prophet, collected as hadith, is an important traditional source that is used to supplement and explicate the Qu'ran. The Sunna is almost as important to Islam as the Qur'an, for in it lie the elaborations of Qur'anic teaching essential to the firm establishment of a world religion. There are disagreements in the hadith, and aspects of interpretations of the Qur'an and the Sunna have varied so much as to be contradictory at times. These situations are resolved by reference to one of the most important of the sayings attributed to the Prophet, "My community will never agree in an error." This leeway also allowed Islam to expand by incorporating social, tribal, and ethnic traditions. For example, with the exception of inheritance and witness laws, Islamic rights and obligations apply equally to men and women. The actual situation of women is more a function of particular social traditions predating Islam than of theoretical positions. For more information on Islamic law, see sharia; for discussions of the major branches of Islamic theology, see Shiite, Sunni.
See F. Rahman, Islam (1966); M. Jameelah, Islam and Modernism (1968); P. K. Hitti, History of the Arabs (10th ed. 1970); P. M. Holt, ed., Cambridge History of Islam (2 vol., 1970); M. G. S. Hodgson, The Venture of Islam (3 vol., 1974); C. Glassé, Concise Encyclopedia of Islam (1991); J. L. Esposito, Islam (rev. ed. 1992) and The Oxford Dictionary of Islam (2003); A. Schimmel, Islam (1992); D. Waines, An Introduction to Islam (1995); J. I. Smith, Islam in America (1999).