Concept

Islam

Intro

Islam is the second-largest religion in the world. About one in four people on the planet practice it. The word Islam in Arabic means submission, and a Muslim is one who submits to God.

It began in seventh-century Arabia. A man named Muhammad (around 570 to 632 AD), born in the trading city of Mecca, began reporting revelations from the angel Gabriel when he was about 40 years old. Over the next 23 years, those revelations were collected into the Quran. He gathered followers, faced opposition, fled to the city of Medina in 622 (the move that starts the Islamic calendar), built a community there, and eventually returned to Mecca as its religious and political leader.

Muslims hold that Muhammad is the last and greatest of God's prophets, the Seal of the Prophets, and that the Quran is God's final word, dictated word-for-word to Muhammad through Gabriel and preserved without change ever since. Earlier prophets, including Adam, Noah, Abraham, Moses, David, and Jesus, are honored, but the messages they brought are said to have been corrupted by their followers. Muslims worship one God (Allah, just Arabic for "the God"), pray five times a day, give to the poor, fast during the month of Ramadan, and try to make a pilgrimage to Mecca at least once in their life.

After Muhammad died in 632, his followers split over who should lead. The majority (today's Sunnis, roughly 85 percent) accepted a series of elected leaders called caliphs. A minority (today's Shia, roughly 15 percent) held that authority should have stayed in Muhammad's bloodline through his cousin and son-in-law Ali. That split has shaped Islamic history ever since.

This page lays out the history, the core beliefs, the practices, and the main places where Christianity and Islam agree, overlap, and sharply diverge.

In full

Islam (Arabic: "submission" to God) is the world's second-largest religion, with approximately 1.9 billion adherents. Founded in 7th-century Arabia through the prophetic career of Muhammad ibn Abdullah (c. 570-632 AD), it is an Abrahamic monotheism holding that God (Allah, from al-Ilah, "the God") revealed his final and definitive word through Muhammad as the Seal of the Prophets. The religion's authoritative sources are the Quran (the direct revelation to Muhammad), the Hadith (reports of Muhammad's words and actions), and the Sunnah (Muhammad's practice as a lived model). Observance is structured around the Five Pillars. Islam divides internally into two primary traditions: Sunni (approximately 85% of adherents) and Shia (approximately 15%).

Origins and history

Muhammad was born in Mecca around 570 AD into the Quraysh tribe, a trading lineage that controlled the Kaaba sanctuary. He received his first revelation in 610 AD on Mount Hira, an experience he reported as overwhelming and initially terrifying. For roughly a decade he preached in Mecca to a small following, facing increasing opposition from the Qurayshi establishment whose economic power was tied to the city's polytheistic religious trade.

The turning point was the Hijra (emigration, 622 AD), Muhammad's migration from Mecca to Medina (then called Yathrib), which marks year 1 of the Islamic calendar (1 AH). In Medina he functioned not only as a prophet but as a political and military leader, establishing a governing community (ummah) through a series of alliances, treaties, and military campaigns. By 630 AD Mecca capitulated and the Kaaba was cleansed of idols.

Muhammad died in 632 without designating an unambiguous successor. The question of succession immediately fractured the community. The majority (proto-Sunni) accepted Abu Bakr as the first Caliph, followed by Umar and then Uthman. A minority maintained that leadership belonged to Ali ibn Abi Talib, Muhammad's cousin and son-in-law. Ali eventually became the fourth Caliph, but his authority was contested. His son Husayn refused allegiance to the Umayyad Caliph Yazid and was massacred with a small company at Karbala (680 AD), an event of definitive theological weight for Shia Islam, commemorated annually during Ashura.

The Umayyad Caliphate (661-750 AD) and Abbasid Caliphate (750-1258 AD) presided over Islam's expansion across North Africa, Iberia, Persia, Central Asia, and into South Asia. The Abbasid period saw the translation movement (bayt al-hikmah, "House of Wisdom" in Baghdad) that preserved and advanced Greek philosophical and scientific works, with significant consequences for medieval European intellectual life via Arab intermediaries.

Core scriptures

The Quran (Arabic: al-Qur'an, "the recitation") consists of 114 chapters (surahs) arranged roughly by length, not chronologically. Muslim tradition holds that Gabriel dictated the Quran to Muhammad verbatim, making it the direct and uncreated speech of God, superior to and superseding prior revelations. The text was standardized c. 650 AD under the third Caliph Uthman, who ordered variant codices burned to ensure a uniform text. Classical Islamic theology affirms the Quran's perfect preservation from the original revelation; this claim is directly contested by source-critical scholarship and by internal Islamic manuscript evidence. See Quranic Corruption and Preservation.

The Hadith are reports of Muhammad's words and deeds transmitted through chains of narration (isnad). An estimated 700,000 hadith circulated in the early period; the classical collectors worked in the 8th and 9th centuries applying isnad-criticism to authenticate narrations. Sunni Islam recognizes six canonical collections (kutub al-sittah): Sahih al-Bukhari, Sahih Muslim, Sunan Abu Dawud, Jami al-Tirmidhi, Sunan al-Nasai, and Sunan Ibn Majah, with Bukhari and Muslim regarded as most reliable (sahih). Shia Islam maintains its own canonical hadith collections, privileging narrations through the Prophet's household (ahl al-bayt) and rejecting narrations transmitted through companions they regard as having betrayed Ali.

The Sunnah refers to Muhammad's normative practice, reconstructed from the Hadith. Together with the Quran it forms the basis of Islamic jurisprudence (fiqh) and religious law (shari'a).

Core doctrines

Tawhid (divine oneness) is Islam's central theological affirmation: God is absolutely one, indivisible, without partners or equals. The Christian doctrine of the Trinity is regarded as shirk (associating partners with God), Islam's most serious theological error. God's attributes are affirmed through the 99 Beautiful Names (asma al-husna), but God's essence remains unknowable.

Prophethood (nubuwwa): God has sent messengers to every people throughout history. The Islamic canon includes Adam, Noah, Abraham, Moses, David, and Jesus (Isa), culminating in Muhammad as the final and definitive prophet, the Seal of the Prophets (khatam al-nabiyyin, Quran 33:40).

Scripture: Prior revelations include the Torah (Tawrat), the Psalms (Zabur), and the Gospel (Injil). Islam holds that Christians and Jews received genuine revelation but subsequently corrupted the texts. See Tahrif.

Predestination (qadar): Everything that occurs is within God's knowledge and decree. How this interacts with human moral responsibility is disputed across the schools of Islamic theology, but the affirmation of divine sovereignty is universal.

Eschatology: A day of judgment (yawm al-din) follows death and resurrection. The righteous enter the garden (jannah), described in richly sensory terms; the unrighteous face the fire (jahannam). The barzakh is an intermediate state between death and judgment.

Shari'a is the comprehensive legal-ethical framework derived from Quran and Sunnah through jurisprudential reasoning. The four major Sunni legal schools (Hanafi, Maliki, Shafi'i, Hanbali) differ in methodology and on specific rulings; Shia jurisprudence constitutes a fifth tradition.

The Five Pillars

Islam's obligatory practice is organized around five foundational duties:

Shahada (testimony): "I bear witness that there is no god but God, and Muhammad is the Messenger of God." Utterance with sincere intention constitutes entry into Islam.
Salah (prayer): Five daily prayers at prescribed times (dawn, noon, afternoon, sunset, night), preceded by ritual purification (wudu), performed facing Mecca (qibla).
Zakat (almsgiving): Obligatory charitable giving, typically calculated as 2.5% of accumulated savings above a minimum threshold (nisab), distributed to specified categories of recipients.
Sawm (fasting): Total abstention from food, drink, and sexual relations during daylight hours throughout the lunar month of Ramadan, commemorating the first revelation to Muhammad.
Hajj (pilgrimage): At least once in a lifetime, every Muslim who is physically and financially able must perform the pilgrimage to Mecca during the designated days of Dhul Hijjah.

See Five Pillars of Islam for the dedicated hub.

Sunni and Shia

The Sunni-Shia divide originates in the succession question of 632 AD but has developed into distinct theological, jurisprudential, and devotional traditions over fourteen centuries.

Sunni Islam accepts the legitimacy of the four "rightly guided" caliphs (Abu Bakr, Umar, Uthman, Ali) and grounds authority in consensus (ijma) of the scholarly community and the six hadith collections. Sunni jurisprudence is organized into four legal schools. Sunni theology is further subdivided between Ashari, Maturidi, and Athari/Salafi schools on questions of divine attributes and human reason.

Shia Islam holds that leadership of the Muslim community was vested by divine appointment in Ali and his descendants, called Imams. The dominant Shia tradition (Twelver Shia, Ithna Ashariyya) holds that twelve Imams succeeded in this line, the last of whom (Muhammad al-Mahdi) went into occultation in 874 AD and will return at the end of time. The Imam possesses spiritual authority beyond mere political leadership, including authoritative interpretation of the Quran. Shia jurisprudence relies on its own hadith collections and grants living senior scholars (marjas) a degree of interpretive authority that has no full Sunni parallel.

Geographically, Sunni Islam is predominant across the Arab world, Turkey, South and Southeast Asia, and sub-Saharan Africa. Shia majorities exist in Iran, Iraq, Azerbaijan, and Bahrain; significant Shia minorities live in Lebanon, Pakistan, Saudi Arabia, and India.

Zaydi Shia (Yemen) and Ismaili Shia (globally dispersed, led by the Aga Khan) represent smaller but historically significant branches.

Sufism

Sufism (tasawwuf) is Islam's mystical-devotional tradition, spanning both Sunni and Shia communities. Sufis seek direct experiential knowledge of God (ma'rifa) through disciplined spiritual practice: rhythmic prayer, meditation, fasting, and in many orders ecstatic movement or music. Sufi orders (tariqas) trace their spiritual lineage through chains of masters back to the Prophet; major orders include the Naqshbandi, Qadiri, Mevlevi (the "whirling dervishes" of Rumi's tradition), and Chishti.

The great Sufi poets, Rumi (1207-1273), Hafiz (c. 1315-1390), and Attar (c. 1145-1221), expressed an ardent theology of divine love that has been widely read outside Islam and provides an important point of contact for Christian apologetic engagement: personal longing for God, the language of love, and the pursuit of virtue arising from devotion rather than mere legal compliance. Sufism has also generated theological controversy within Islam, with Salafi and Wahhabi movements condemning as shirk practices such as veneration at saints' tombs.

Christian apologetic engagement

Points of contact

Rigorous monotheism: Both traditions affirm one personal Creator God, distinct from creation, who speaks and acts in history.
Scriptural seriousness: Islam's treatment of the Quran as God's word parallels (and indeed exceeds in formal authority-claims) Christian high-view-of-Scripture commitments. The conversation about textual transmission is therefore native to both.
Moral seriousness: Islam's ethical framework, its condemnation of idolatry, sexual immorality, injustice, and greed, overlaps substantially with biblical ethics. Muslim and Christian voices often align in public moral discourse.
Respect for Jesus (Isa): The Quran affirms Jesus' virgin birth (Surah 19), his miraculous works, his title "Word of God" (Kalimatullah, Surah 4:171), and his eschatological role as returning judge. This provides significant common ground for Christologically-focused apologetic conversation.
Prayer, fasting, and almsgiving are structural parallels to Christian practice. The commonality can open relational dialogue.

Points of divergence

The Trinity: Islam defines the Trinity as tri-theism and condemns it as shirk. The Quran's anti-Trinitarian polemic (Surah 5:73, 5:116) appears to target a Father-Mary-Jesus triad, not the classical Trinity. This provides an apologetic opening: the Trinity Islam explicitly condemns may not be the Trinitarian formula historic Christianity actually holds. See Trinity.
The Crucifixion: Islam denies that Jesus was crucified (Surah 4:157: "they did not kill him nor did they crucify him, but it was made to appear so to them"). This denial contradicts the earliest and most solidly attested fact in ancient history about Jesus, affirmed by Tacitus, Josephus, and every strand of the New Testament. See Crucifixion Denial in Islam.
Quranic Christology vs biblical Christology: Islam affirms Jesus as prophet and Messiah but denies his divine sonship and atoning death. The apologetic question is whether the Quran's own high Christological language (Word of God, Spirit from God, sinless, virgin-born, miracle-worker, returning judge) is coherent on a merely-prophet reading. See Kalimatullah.
Salvation: Islam teaches that salvation is achieved through faith, practice of the Five Pillars, and God's mercy, with no need for atoning sacrifice. The Christian gospel claims the fundamental human problem is guilt before a just God, requiring substitutionary atonement, which Islam structurally cannot accommodate because it denies both original sin and the Crucifixion.
Biblical reliability (Tahrif): Muslim polemics claim Christians and Jews corrupted the Torah and Gospel (tahrif, "distortion"). The Quran itself affirms the Torah and Gospel as God's authentic revelation at Muhammad's time (Surah 5:46-47, 10:94). If the texts were reliable in Muhammad's day, the manuscript tradition from that period to the present shows no corruption; if corrupted before Muhammad's day, the Quran's own commands to consult them are incoherent. See Tahrif and Islamic Dilemma.

The Islamic Dilemma

The Quran repeatedly affirms the Torah and Gospel as authentic divine revelation and directs Muhammad's contemporaries to consult them (Surah 10:94, 5:46-47). Simultaneously, Islamic polemics claim these scriptures were subsequently corrupted by Jews and Christians. The dilemma: if the corruption occurred after Muhammad, the manuscripts from his era forward show no such corruption (textual criticism); if it occurred before Muhammad, the Quran's own endorsements are endorsements of fraudulent documents. Either horn undermines the Islamic account of biblical history. See Islamic Dilemma.

Quranic Christology

The Quran's treatment of Jesus is formally lower than Christian orthodoxy but formally higher than a generic prophet:

Surah 4:171: "O People of the Book, do not commit excess in your religion or say about Allah except the truth. The Messiah, Jesus the son of Mary, was no more than a messenger of Allah and His Word (kalimatuhu) which He directed to Mary and a soul from Him." The Quran bestows "Word of God" and "Spirit from God" on Jesus while denying divinity. Classical Islamic exegetes work hard to limit these titles; the apologetic question is whether the limitation succeeds. See Kalimatullah.
Surah 5:75: "The Messiah, son of Mary, was no more than a messenger; many messengers had come before him. His mother was truthful, and both of them ate food." The argument from eating food against divinity misunderstands Christian Christology (the incarnation affirms that Christ ate); the argument proves less than it appears.
Surah 19 (Maryam): The fullest Quranic nativity account, affirming the virgin birth, the infant Jesus speaking from the cradle, and his prophetic mission.
Surah 3:55: God says to Jesus "I will cause you to die (mutawaffika) and raise you to Myself." The verb tawaffa is disputed: classical interpreters read it as "take you up" without death, or as referring to a future death after return; it has become a key proof-text in both directions in Christian-Muslim debate.
Surah 4:157-158: "They did not kill him nor did they crucify him, but it was made to appear so to them... Rather, Allah raised him up to Himself." The Quran's denial of the crucifixion is one of the most historically indefensible claims of any major world religion, given the unanimity of ancient sources. See Crucifixion Denial in Islam.

Demographics

Islam is the world's second-largest religion at approximately 1.9 billion adherents (c. 24% of global population) and by most projections will rival or exceed Christianity in global membership by 2070-2100 due to higher birth rates and younger median age in Muslim-majority populations. Geographic concentration is highest in the Middle East and North Africa (MENA), South Asia (Pakistan, Bangladesh, India's Muslim minority of c. 200 million), and Southeast Asia (Indonesia is the world's largest Muslim-majority country at c. 230 million). Sub-Saharan Africa has one of the fastest-growing Muslim populations. Western diasporas, particularly in France, Germany, the UK, and the United States, form significant minority communities with growing apologetic and missiological relevance.

Notable Christian-Muslim dialogue and apologetics figures

Modern:

Nabeel Qureshi (1983-2017) converted from Ahmadiyya Islam to Christianity after sustained engagement with the historical evidence for the resurrection, documented in Seeking Allah, Finding Jesus (2014); later addressed Islamic apologetics from a Christian perspective. See Nabeel Qureshi (Conversion 2003-2014).
James White (Alpha and Omega Ministries) has engaged in formal cross-confessional debates on the Quran, the Trinity, and the Crucifixion with Muslim scholars.
David Wood (Acts 17 Apologetics) focuses on Islamic source-criticism: Quranic textual history, Hadith violence, and Christological arguments from the Quran itself.
Jay Smith (Pfander Films/Centre) has debated Islamic scholars at Speakers' Corner and produced extensive material on Quranic manuscript history.
Mark Durie (linguist and Anglican minister) examines Islamic theology and shari'a in relation to Christian and Western legal frameworks.
Sam Solomon (former Islamic jurist, convert) addresses shari'a and Islamic law from an insider perspective.
Ravi Zacharias engaged Muslim audiences in formal settings in the Middle East and at Oxford, stressing the questions of suffering, love, and meaning.

Historical:

Raymond Lull (c. 1232-1316), Catalan philosopher and missionary who argued for reasoned dialogue with Muslims and repeatedly traveled to North Africa; martyred in Tunis.
Henry Martyn (1781-1812), Cambridge scholar and Anglican missionary in India and Persia; translated the New Testament into Urdu, Persian, and Judeo-Persian; engaged Persian Muslim scholars in formal theological exchange.
Samuel Zwemer (1867-1952), "Apostle to Islam," worked in the Arabian Peninsula and Egypt, produced extensive scholarship on Islamic theology and the doctrine of God.

Common questions this page answers

Q: What about Islam?

Islam shares some patrimony with Christianity (one God, the Abrahamic stream) but diverges at structurally decisive points: the Trinity (denied), the Incarnation (denied), the crucifixion (denied per Q 4:157-158), the resurrection (denied), Christ's deity (denied), justification by faith alone (denied). The historical claims of Islam (Muhammad's prophethood, the Quran's preservation) face independent evidential and textual problems.