History & Origins
Islam emerged in the early 7th century CE in the Arabian Peninsula, when the merchant Muhammad ibn Abdullah received what he understood to be divine revelation through the angel Jibril (Gabriel) in a cave outside Mecca. Within a century of his death, Islam had spread from Spain to Central Asia, becoming one of the most consequential religious and civilizational forces in human history.
The word Islam derives from the Arabic root s-l-m, meaning peace, submission, and wholeness. A Muslim is "one who submits" — specifically, one who submits to God (Allah, the Arabic word for the one God). Islam understands itself not as a new religion but as the restoration of the pure monotheism of Abraham (Ibrahim), whom it regards as the first Muslim in the broader sense: one who submitted wholly to God.
Muhammad was born in Mecca around 570 CE into the Quraysh tribe. At approximately age 40, during the month of Ramadan in 610 CE, he received his first revelation while meditating in the Cave of Hira on Mount Nur. These revelations continued for 23 years until his death in 632 CE and were eventually compiled into the Quran. The earliest revelations emphasized the oneness of God, the coming Day of Judgment, care for the poor and orphaned, and rejection of the polytheism prevalent in Arabian society.
"There is no god but God, and Muhammad is the messenger of God."
The Shahada — The Islamic declaration of faith, the first of the Five PillarsMuhammad's preaching met fierce resistance from Meccan elites whose economic interests were tied to the Kaaba's polytheistic shrine complex. In 622 CE, after sustained persecution, Muhammad and his followers emigrated to Medina in an event known as the Hijra, which marks the beginning of the Islamic calendar. In Medina, Muhammad assumed both prophetic and political authority, establishing the first Muslim community (ummah) and negotiating the Constitution of Medina, an agreement between Muslim, Jewish, and pagan Arab tribes.
In 630 CE, a Muslim army entered Mecca largely without bloodshed. Muhammad cleansed the Kaaba of its idols and established it as the focal point of Muslim prayer worldwide. After his death in 632 CE, his companion Abu Bakr was elected as the first caliph (successor), and the Muslim community rapidly expanded through the Arabian Peninsula, Persia, Byzantine Syria, Egypt, and beyond. The early caliphate era, while marked by great missionary and military success, also experienced the first major schism in Muslim history — the question of succession that gave rise to the Sunni-Shia division.
The subsequent centuries saw the Umayyad and Abbasid caliphates preside over a golden age of Islamic civilization, during which Muslim scholars made foundational contributions to mathematics, astronomy, medicine, philosophy, and literature. The translation movement centered in Baghdad's House of Wisdom preserved and extended classical Greek knowledge. Figures such as Al-Kindi, Ibn Sina (Avicenna), Al-Biruni, and Ibn Rushd (Averroes) shaped intellectual history far beyond the Muslim world.
Core Beliefs & Theology
Islamic theology is anchored in the doctrine of Tawhid — the absolute, indivisible oneness of God. All other beliefs flow from this foundation. Alongside Tawhid, the Six Articles of Faith define the core doctrinal commitments of every Muslim.
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ITawhid — The Oneness of God (Allah)
God is one, without partner, equal, or offspring. He is eternal, self-subsistent, omniscient, and omnipotent. The Quran's 112th chapter (Al-Ikhlas) is the most concentrated expression of Tawhid: "Say: He is God, the One; God, the Eternal Refuge; He neither begets nor is born; nor is there to Him any equivalent." Shirk — associating partners with God — is the one unforgivable sin if maintained until death.
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IIBelief in Angels (Mala'ika)
Angels are spiritual beings created from light who serve God without will or desire. They carry out divine commands, record human deeds (the angels Raqib and Atid), and include the archangels Jibril (Gabriel, who brought revelation to the prophets), Mika'il (Michael), Israfil (who will sound the trumpet at the Last Day), and Izra'il (the angel of death).
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IIIBelief in the Revealed Books (Kutub)
God has sent scriptures to prophets throughout history: the Suhuf (Scrolls) to Abraham, the Tawrat (Torah) to Moses, the Zabur (Psalms) to David, and the Injil (Gospel) to Jesus. Muslims believe these earlier scriptures have been corrupted over time. The Quran is God's final and perfectly preserved revelation, superseding all previous scriptures.
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IVBelief in the Prophets (Anbiya)
God sent 124,000 prophets (according to one hadith) to guide humanity, beginning with Adam. The Quran names 25 by name, including Ibrahim (Abraham), Musa (Moses), Isa (Jesus), and Dawud (David). Muhammad is the last and greatest prophet — the "Seal of the Prophets" (Khatam an-Nabiyyin) — after whom no new prophet will come. All prophets conveyed the same essential message of Tawhid.
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VBelief in the Day of Judgment (Yawm al-Qiyama)
History will end with a final day of resurrection and judgment. All human beings will be resurrected and their deeds weighed. Those whose good deeds outweigh the bad will enter Jannah (Paradise), described in the Quran as a garden of spiritual and physical bliss. Those whose evil outweighs the good will face Jahannam (Hell). God's mercy, however, is emphasized throughout: "My mercy encompasses all things" (Quran 7:156).
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VIBelief in Divine Decree (Qadar)
God has foreknowledge of all things and all events occur within His will and plan. This belief, however, is understood to coexist with human free will and moral responsibility — a tension explored extensively in Islamic theology. The tradition of Ash'ari and Maturidi theology developed sophisticated frameworks for reconciling divine omniscience with human agency.
Islamic Law — Shari'a
Shari'a (literally "the way to the watering hole") is the comprehensive moral and legal framework derived from the Quran and Sunna. It governs worship, personal ethics, family law, commercial transactions, and governance. Classical shari'a was developed by legal scholars (fuqaha) through four major Sunni legal schools (madhabs) — Hanafi, Maliki, Shafi'i, and Hanbali — and the Shia Ja'fari school. Shari'a represents the ongoing project of discerning God's will for human conduct across all domains of life.
Sacred Texts
The Quran is the central sacred text of Islam — the literal word of God as received by Muhammad and preserved without alteration. Alongside it, the Hadith literature records the words, actions, and tacit approvals of the Prophet and forms the basis of the Sunna.
Key Figures
Islamic history produced scholars, mystics, jurists, and rulers whose thought shaped not only the Muslim world but the entire trajectory of medieval and modern civilization.
Practices & Observances
Islamic practice is structured around the Five Pillars — the non-negotiable obligatory acts of worship — along with a comprehensive ethical and legal framework governing diet, family life, finance, and social conduct.
The first Pillar and the entry point into Islam: "Ashhadu an la ilaha ill Allah, wa ashhadu anna Muhammadan rasul Allah" — "I bear witness that there is no god but God, and I bear witness that Muhammad is the messenger of God." Sincerely uttered before witnesses, this declaration constitutes conversion to Islam. It is recited in the call to prayer, in daily prayers, and is ideally the last utterance of a Muslim's life.
Five daily prayers performed at prescribed times: Fajr (dawn), Dhuhr (midday), Asr (afternoon), Maghrib (sunset), and Isha (night). Each prayer involves ritual purification (wudu), facing Mecca, recitation of Quranic verses, and a prescribed sequence of standing, bowing, and prostration (raka'at). Friday midday prayer (Jumu'ah) is a communal obligation for men and includes a sermon (khutba). Prayer is the most regular act of devotion binding Muslims to God throughout each day.
The third Pillar requires Muslims who possess wealth above a minimum threshold (nisab) for a full lunar year to give 2.5% of that wealth annually to prescribed categories of recipients: the poor, the indebted, travelers in need, and others. Zakat is a religious obligation, not voluntary charity — it is understood as a purification of wealth. It represents one of Islam's most direct mechanisms for economic redistribution and social welfare.
During the lunar month of Ramadan — commemorating the first revelation of the Quran — adult Muslims abstain from food, drink, smoking, and sexual relations from dawn (Fajr) to sunset (Maghrib) each day. The fast is broken nightly with iftar and preceded before dawn by suhoor. The last ten nights, particularly Laylat al-Qadr ("the Night of Power," when the first revelation descended), are devoted to intensified prayer and Quran recitation. Ramadan concludes with the festival of Eid al-Fitr.
Every physically and financially able Muslim must perform the Hajj pilgrimage to Mecca at least once in a lifetime. Conducted during the Islamic month of Dhul Hijja, the Hajj involves a series of rituals including the Tawaf (seven circumambulations of the Kaaba), the Sa'i (walking between the hills of Safa and Marwa), the gathering at the plain of Arafat, and symbolic stoning of the devil at Mina. It concludes with Eid al-Adha. With 2–3 million participants annually, it is the world's largest annual human gathering.
Islamic dietary law distinguishes between halal (permitted) and haram (forbidden) foods. Pork and its by-products, alcohol and intoxicants, blood, and animals not slaughtered in God's name are forbidden. Permitted animals must be slaughtered by a Muslim (or People of the Book, in most scholarly opinion) with a swift cut to the jugular while invoking God's name. The concept of halal and haram extends beyond food to financial transactions (prohibition of riba/interest), entertainment, and personal conduct.
The practice of remembering God through repetitive recitation of divine names or phrases. Common formulas include Subhanallah ("Glory be to God"), Alhamdulillah ("All praise is due to God"), Allahu Akbar ("God is the Greatest"), and La ilaha ill Allah. Dhikr is practiced by all Muslims after prayer and throughout daily life; in Sufi orders it becomes an intensive group practice, sometimes accompanied by music and movement, aimed at dissolution of the ego in the awareness of God.
The recitation of the Quran in Arabic according to the rules of tajweed (proper pronunciation and rhythm) is itself an act of worship. Entire communities follow the practice of completing the Quran during Ramadan. The tradition of Hifz — memorizing the entire Quran — is among the most honored religious accomplishments in Islam, with millions worldwide carrying the complete text in memory. Professional reciters (Qurra) are celebrated for the beauty and precision of their recitation.
Major Branches & Movements
The primary division in Islam arose from the question of political and spiritual succession after Muhammad's death. This produced the Sunni-Shia split, still the most significant structural division in the Muslim world.
Sunni Islam (from Ahl al-Sunna wa'l-Jama'a — "People of the Prophetic Tradition and Community Consensus") holds that Muhammad did not designate a specific successor and that the community legitimately elected Abu Bakr as first Caliph. Sunnis follow one of four legal schools (Hanafi, Maliki, Shafi'i, Hanbali) and generally two theological schools (Ash'ari and Maturidi). Sunni Islam encompasses an enormous diversity of practice and culture across the Muslim-majority world.
Shia Islam (from Shi'at Ali — "Party of Ali") holds that Muhammad explicitly designated his cousin and son-in-law Ali ibn Abi Talib as his rightful successor. The tragic death of Ali and the massacre of his son Husayn ibn Ali at Karbala (680 CE) are defining events of Shia religious consciousness, commemorated annually in the rituals of Ashura. The largest Shia branch, Twelver Shia Islam, recognizes twelve infallible Imams descended from Ali, the last of whom is believed to be in occultation until the end of time. Iran, Iraq, Bahrain, and parts of Lebanon and Pakistan have significant Shia majorities.
A branch of Shia Islam that diverged over the question of the seventh Imam. Ismailis recognize Ismail ibn Jafar (d. 755 CE) as the rightful seventh Imam, unlike Twelvers who followed his brother Musa al-Kazim. The largest contemporary Ismaili community follows the Aga Khan as their living Imam. Historically, the Fatimid Caliphate (909–1171 CE) was an Ismaili state; Ismaili missionaries produced significant philosophical and esoteric literature.
Sufism is the mystical dimension of Islam, concerned with the inner, experiential, and spiritual aspects of the faith — the purification of the soul and direct experience of God's presence. Organized into orders (tariqa) each tracing a spiritual lineage (silsila) back to the Prophet, major Sufi orders include the Qadiriyya, Naqshbandiyya, Shadhiliyya, Tijaniyya, and Mevlevi. Sufism has been both a vehicle for the spread of Islam — particularly in sub-Saharan Africa, South Asia, and Central Asia — and a recurring subject of controversy with more literalist strands of Sunni thought.
A purist reform movement advocating a return to the practices of the "pious ancestors" (al-Salaf al-Salih — the first three generations of Muslims). Founded in 18th-century Arabia by Muhammad ibn Abd al-Wahhab, who allied with the house of Saud, the movement rejects practices it considers innovations (bid'a), including many Sufi practices, saint veneration, and elaborate theological speculation. Wahhabi/Salafi scholarship, substantially funded by Saudi oil wealth, has had widespread influence on Muslim communities globally since the late 20th century.
The oldest surviving Islamic school of thought, predating the Sunni-Shia split and descending from the early Kharijite movement (though Ibadis reject this label). Ibadis reject the idea that the caliphate must belong to any specific tribe or lineage, holding that the leader must be the most pious and qualified person regardless of origin. They practice a moderate, non-militant theology distinct from both Sunni and Shia mainstream. Ibadi Islam is the official religion of Oman and has communities in Libya, Tunisia, Algeria, and Zanzibar.
Glossary of Key Terms
A reference guide to essential Arabic terms in Islamic theology, law, and practice.
The Arabic word for God — not a personal name but the definite form of "ilah" (deity). Pre-Islamic Arabs used the term; Islam retained it with the radical insistence on its referent's absolute oneness. Arabic-speaking Christians also use "Allah" for God. The Quran provides 99 "Beautiful Names" (Asma ul-Husna) — such as Al-Rahman (the Most Merciful) and Al-Rahim (the Especially Merciful) — describing divine attributes.
The central sacred text of Islam, regarded as the literal word of God revealed to Muhammad through Jibril over 23 years (610–632 CE). It comprises 114 suras of varying length. The Quran is unique among world scriptures in that its language (Classical Arabic) is considered sacred and inimitable; translation into other languages is understood as an interpretation, not the Quran itself.
The comprehensive moral and legal code of Islam derived from the Quran, Sunna, scholarly consensus (ijma), and analogical reasoning (qiyas). Often mistranslated as "Islamic law" alone, Shari'a encompasses the totality of God's guidance for human life — including worship, ethics, diet, commerce, and family law. Its practical application has always involved scholarly interpretation and has varied significantly across time and culture.
Often misrepresented in Western discourse, jihad means "striving in the path of God." The classical tradition distinguishes between the "greater jihad" (al-jihad al-akbar) — the inner spiritual struggle against one's own ego and moral failings — and the "lesser jihad" (al-jihad al-asghar) — military defense of the Muslim community under strictly regulated conditions. The latter has detailed rules of engagement developed in classical Islamic jurisprudence that prohibit targeting civilians, destroying crops, and killing the elderly.
The global community of Muslim believers, transcending national, ethnic, and linguistic boundaries. The concept of ummah is foundational to Islamic social thought — Islam is not merely a private religion but a community bond. The Constitution of Medina (622 CE) is the earliest document establishing the concept of a multi-religious ummah under Muhammad's leadership. Consciousness of belonging to a worldwide ummah remains a powerful force in Muslim political and religious identity.
In Sunni Islam, an imam is a prayer leader who leads congregational worship — a functional, not necessarily clerical role, though mosque imams typically have religious training. In Shia Islam, "Imam" carries an entirely different and elevated meaning: the divinely guided, infallible leader of the Muslim community from the lineage of Ali ibn Abi Talib, whose authority encompasses both political and religious guidance.
A report of a saying, action, or tacit approval of the Prophet Muhammad, transmitted through a chain of narrators (isnad). Hadith scholarship developed an elaborate science of authentication based on the reliability of each narrator in the chain. Reports are classified as sahih (sound), hasan (good), da'if (weak), or mawdu (fabricated). Together with the Quran, the hadith literature is the primary basis for Islamic law and practice.
The ritual ablution required before performing salat (prayer) and handling the Quran. It involves washing the hands, mouth, nose, face, forearms, head, ears, and feet in a prescribed sequence. Wudu must be renewed if it is broken by sleep, use of the toilet, or other specified events. A full ritual bath (ghusl) is required after sexual intercourse, menstruation, childbirth, and other states of major ritual impurity.
The central doctrine of Islamic theology: the absolute oneness and uniqueness of God. Tawhid encompasses three dimensions in classical theology: oneness of lordship (rububiyya — God alone sustains creation), oneness of divine names and attributes (asma wa sifat), and oneness of worship (uluhiyya — God alone deserves worship). Shirk — associating any partner, peer, or equal with God — is the gravest of all sins in Islam.
The Quran's vivid descriptions of the afterlife present Jannah (Paradise) as a garden of eternal bliss — rivers of water, milk, honey, and wine; spiritual fulfillment; and the beatific vision of God. Jahannam (Hell) is described as a place of fire and torment for the unrepentant. Classical theology debates whether Hell is eternal for all its inhabitants or whether God's mercy ultimately empties it; many scholars hold that Hell is ultimately finite for Muslims.
The process by which a qualified Islamic jurist (mujtahid) exercises independent reasoning to derive legal rulings on new questions not explicitly addressed by the Quran or Sunna. The "gates of ijtihad" were historically considered "closed" after the major schools were established, though contemporary scholars increasingly argue they must remain open. Ijtihad is central to debates about Islamic law's capacity to engage modernity.
Divine blessing or spiritual power that flows through sacred persons, objects, and places. The concept is foundational to Sufi practice and popular Islam, manifested in the veneration of shrines of saints and the seeking of blessing through proximity to holy persons. Salafi and Wahhabi movements largely reject the concept of barakah as it applies to human beings, seeing it as a corruption of pure monotheism. The tension between these views represents one of the most consequential theological disputes in contemporary Islam.