Islam is a system of religious beliefs and an allencompassing way of life. Muslims believe that God (Allah) revealed to the Prophet Muhammad the rules governing society and the proper conduct of society's members. It is incumbent on the individual, therefore, to live in a manner prescribed by the revealed law and incumbent on the community to build the perfect human society on earth according to holy injunctions. Islam recognizes no distinctions between the religious institution and the state. The distinction between religious and secular law is a recent development that in part reflects the more pronounced role of the state in society and Western economic and cultural penetration. The impact of religion on daily life in Muslim countries is extensive, usually greater than that found in the West.
The area that constitutes the present-day Persian Gulf states was on the immediate periphery of the rise of Islam. In A.D. 610, Muhammad - a merchant of the Hashimite branch of the ruling Quraysh tribe in the Arabian town of Mecca - began to preach the first of a series of revelations that Muslims believe was granted him by God, some directly and some through the angel Gabriel. A fervent monotheist, Muhammad denounced the polytheism of his fellow Meccans. Because the town's economy was based in part on a thriving pilgrimage business to the shrine called the Kaaba and to numerous other pagan religious sites in the area, his censure earned him the enmity of the town's leaders. In 622 he and a group of followers accepted an invitation to settle in the town of Yathrib, later known as Medina (the city), because it was the center of Muhammad's activities. The move, or hijra, known in the West as the hegira, marks the beginning of the Islamic era and of Islam as a force in history; the Muslim calendar begins in 622. In Medina, Muhammad continued to preach, and he eventually defeated his detractors in battle. He consolidated the temporal and the spiritual leadership in his person before his death in 632. After Muhammad's death, his followers compiled those of his words regarded as coming directly from God into the Quran, the holy scripture of Islam. Others of his sayings, recalled by those who had known him, became the hadith. The precedent of Muhammad's deeds is called the sunna. Together they form a comprehensive guide to the spiritual, ethical, and social life of an orthodox Sunni Muslim.
The major duties of Muslims are found in the five pillars of Islam, which set forth the acts necessary to demonstrate and reinforce the faith. These are the recitation of the shahada ("There is no god but God [Allah], and Muhammad is his prophet"), daily prayer (salat), almsgiving (zakat), fasting (sawm), and pilgrimage (hajj). The believer is to pray in a prescribed manner after purification through ritual ablutions each day at dawn, midday, midafternoon, sunset, and nightfall. Prescribed genuflections and prostrations accompany the prayers, which the worshiper recites while facing toward Mecca. Whenever possible, men pray in congregation at the mosque with an imam, and on Fridays they are required to do so. The Friday noon prayers provide the occasion for weekly sermons by religious leaders. Women may also attend public worship at the mosque, where they are segregated from the men, although most frequently women pray at home. A special functionary, the muezzin, intones a call to prayer to the entire community at the appropriate hour.
The ninth month of the Muslim calendar is Ramadan, a period of obligatory fasting in commemoration of Muhammad's receipt of God's revelation. Throughout the month, all but the sick and the weak, pregnant or lactating women, soldiers on duty, travelers on necessary journeys, and young children are enjoined from eating, drinking, smoking, or sexual intercourse during the daylight hours. Those adults excused are obliged to endure an equivalent fast at their earliest opportunity. A festive meal breaks the daily fast and inaugurates a night of feasting and celebration. The pious well-to-do usually do little or no work during this period, and some businesses close for all or part of the day. Because the months of the lunar year revolve through the solar year, Ramadan falls earlier in the solar year each successive year. A considerable test of discipline at any time of the year, a fast that falls in summer imposes severe hardship on those who must do physical work.
All Muslims, at least once in their lifetimes and if circumstances permit, should make the hajj to Mecca to participate in special rites held there during the twelfth month of the lunar calendar. Muhammad instituted this requirement, modifying pre-Islamic custom, to emphasize sites associated with God and Abraham (Ibrahim), founder of monotheism and father of the Arabs through his son, Ismail.
The lesser pillars of the faith, which all Muslims share, are jihad, or the permanent struggle for the triumph of the word of God on earth, and the requirement to do good works and to avoid all evil thoughts, words, and deeds. In addition, Muslims agree on certain basic principles of faith based on the teachings of the Prophet Muhammad: there is one God, who is a unitary divine being in contrast to the trinitarian belief of Christians; Muhammad, the last of a line of prophets beginning with Abraham and including Moses and Jesus, was chosen by God to present God's message to humanity; and there is a general resurrection on the last, or judgment, day.
During his lifetime, Muhammad held both spiritual and temporal leadership of the Muslim community. Religious and secular law merged, and all Muslims have traditionally been subject to the sharia, or religious law. A comprehensive legal system, the sharia developed gradually through the early centuries of Islam, primarily through the accretion of interpretations and precedents set by various judges and scholars. During the tenth century, legal opinion began to harden into authoritative rulings, and the figurative bab al ijtihad (gate of interpretation) closed. Thereafter, rather than encouraging flexibility, Islamic law emphasized maintenance of the status quo.
After Muhammad's death, the leaders of the Muslim community consensually chose Abu Bakr, the Prophet's father-in-law and one of his earliest followers, to succeed him. At that time, some persons favored Ali ibn Abu Talib, Muhammad's cousin and the husband of his daughter, Fatima, but Ali and his supporters (the Shiat Ali, or Party of Ali) eventually recognized the community's choice. The next two caliphs (successors)--Umar, who succeeded in 634, and Uthman, who took power in 644 - enjoyed the recognition of the entire community. When Ali finally succeeded to the caliphate in 656, Muawiyah, governor of Syria, rebelled in the name of his murdered kinsman, Uthman. After the ensuing civil war, Ali moved his capital to Iraq, where he was murdered shortly thereafter.
Ali's death ended the last of the so-called four orthodox caliphates and the period in which the entire community of Islam recognized a single caliph. Muawiyah proclaimed himself caliph from Damascus. The Shiat Ali refused to recognize him or his line, the Umayyad caliphs, and withdrew in the great schism of Islam to establish the dissident sect, known as the Shia, who supported the claims of Ali's line to the caliphate based on descent from the Prophet. The larger faction, the Sunnis, adhered to the position that the caliph must be elected, and over the centuries they have represented themselves as the orthodox branch.