When Christianity First Encountered Islam

The first private meeting between a Christian and Muhammad cannot be identified with certainty. Arabia already contained Christian tribes, monasteries, merchants, and bishops, while later Islamic tradition describes conversations with Christians. No contemporary Christian account of those discussions survives. What history can identify is the earliest surviving Christian reaction to the movement that became Islam.

That reaction appeared during the 630s, when Arab armies entered lands that had been Christian for centuries. The first witnesses did not yet possess a developed account of Qur’anic theology. They saw armed forces advancing under a prophetic claim, cities falling, and teachings about Jesus that contradicted the Gospel. Systematic argument came later, above all in Saint John of Damascus.

The Christian World Islam Entered

Islam arose beside a Christian world extending from North Africa through Egypt, Palestine, Syria, Armenia, Mesopotamia, and Persia. Egypt was overwhelmingly Christian at the conquest, while Christians remained the majority in many territories under Muslim rule for centuries. ^[1]

The Christian East was divided. Chalcedonian Christians remained in communion with Rome and Constantinople, while Coptic, Syriac, Armenian, and East Syriac churches were separated by earlier controversies. It would therefore be inaccurate to call every eastern Christian a Roman Catholic. Yet they shared the doctrines Islam would challenge: the Trinity, the eternal divinity of the Son, His Incarnation from the Virgin Mary, His real death upon the Cross, and His bodily Resurrection.

The Earliest Christian Witnesses

One of the earliest surviving references appears in the Teaching of Jacob Newly Baptized, usually dated to the late 630s or shortly afterward. It is an anti-Jewish Christian dialogue, not a neutral biography of Muhammad, and some of its information is confused. Nevertheless, it reports news that “a prophet appeared, coming with the Saracens,” followed by the question, “Do prophets come with swords and chariots?” ^[2]

That question expresses the first Christian objection: military victory cannot prove revelation. A prophetic claimant must be judged by his agreement with what God has already revealed, by the witness supporting his mission, and by the fruits of his teaching. Conquest could transfer political power, but it could not authorize someone to revise the identity of Christ.

Saint Sophronius, the Catholic Patriarch of Jerusalem, gives an even more immediate witness. In his Christmas sermon of 634, he lamented that Christians could not make the customary pilgrimage to Bethlehem because of the Saracen advance. ^[3] He interpreted the disaster through the biblical language of chastisement and called Christians to repentance. His response was not yet a developed refutation of Islam. It was the response of a bishop watching the Christian Holy Land become a battlefield. Jerusalem surrendered to Caliph Umar in 637 or 638, making the encounter political as well as theological.

Conquest and the Loss of Christian Rule

The conquests proceeded rapidly. Syria and Palestine fell during the 630s, Egypt during the 640s, and Muslim armies moved through Mesopotamia, Persia, Armenia, North Africa, and eventually Spain.

The seventh-century Armenian historian known as Sebeos provides one of the earliest substantial non-Muslim accounts. He describes Muhammad as a merchant who taught the Arabs to worship the God of Abraham and united them around a claim to the Promised Land. He also records invasion, killing, pillage, and captivity in Armenia, including the violent capture of Dvin. ^[4] His account preserves how Armenian Christians experienced the expansion.

The Coptic bishop John of Nikiu reports that Muslim forces entered Nikiu and killed people found in streets and churches, including women and children. He also states that taxes on peasants were doubled, property was seized, and inhabitants fled in panic. ^[5] Its hostile rhetoric and complicated transmission require caution. The realities he describes, however, belong to war and subjugation: massacre in some places, confiscation, tribute, displacement, and the end of Byzantine government.

John also records facts that prevent oversimplification. Byzantine officials had persecuted non-Chalcedonian Copts before the invasion. Under Muslim rule, the exiled Coptic Patriarch Benjamin was permitted to return, and John says that the commander Amr protected church property during his administration while still imposing heavy taxation. Early Muslim rule was therefore neither universal extermination nor religious equality. Policy varied by ruler, place, and period.

How Christian Majorities Became Minorities

Military conquest was rapid; Islamization was gradual. The great majority of Egyptians were Christian when the conquest began, and their transition from majority to minority unfolded across centuries. ^[6] Christians likewise remained numerically dominant in many conquered territories well into the medieval period. ^[7]

It is therefore false to claim that every Christian was immediately forced to convert at sword point. Churches, monasteries, bishops, liturgies, and Christian officials continued under the caliphates. Yet it is also misleading to describe this arrangement as equal toleration. The Qur’an commands fighting certain “People of the Book” until they pay the jizya in submission. ^[8] Muslim governments gradually developed the subordinate protected status known as dhimma. Christians could ordinarily retain their faith and institutions, but Muslims held the dominant political and legal position. Restrictions on churches, public worship, dress, testimony, and office varied across periods.

Conversion occurred for mixed reasons. Some accepted Islam sincerely; others sought tax relief, legal advantage, security, marriage, advancement, or access to the ruling culture. Arabic increasingly displaced Greek, Coptic, and Syriac in public life. Over time, Egypt, Syria, Palestine, Mesopotamia, and North Africa, once major centers of Christian civilization, became predominantly Muslim. The survival of ancient eastern churches shows Christian endurance, while their reduced condition reflects the consequences of conquest and unequal rule.

The Christian Argument Against Islam

The Qur’an calls Jesus the Messiah, associates Him with God’s Word, and affirms His birth from the Virgin Mary. It also denies His divine Sonship, rejects the Trinity as Islam understands it, and denies that He was truly crucified. ^[9] For Christians, these claims contradicted the center of revelation.

Saint John’s Gospel declares that the Word was with God, was God, created all things, and became flesh. ^[10] Christ commanded baptism in the one name of the Father, Son, and Holy Spirit. Saint Paul identified Christ’s death, burial, Resurrection, and appearances as the Gospel of “first importance,” and warned that even an angel could not authorize a different gospel. ^[11]

The early Christian answer rested on the public and prior character of apostolic revelation. Christianity had been preached openly across nations, preserved in churches founded by the apostles, confessed by martyrs, and celebrated continuously in the Eucharist. A message appearing six centuries later could not correct the Gospel by denying the truths upon which the Church had existed from the beginning.

Saint John of Damascus Gives the First Systematic Answer

Saint John of Damascus, born under the Umayyad caliphate and later a monk near Jerusalem, produced the first major Christian theological treatment of Islam. In On Heresies, he classified it as the “heresy of the Ishmaelites.” ^[12] That description reflects his eighth-century perspective; Islam is more accurately treated today as a separate post-Christian religion. His arguments remain important because he knew the Muslim environment and addressed specific Islamic claims.

First, John challenged Muhammad’s prophetic authority. What witnesses established his mission? What earlier revelation clearly foretold him? What publicly attested signs authorized him to correct the universal Church? Military success could not substitute for divine testimony.

Second, John pressed the Islamic language concerning Christ as God’s Word and Spirit. God has never existed without His Word and Spirit. The Word is not an external creature added to God. John’s wider theology explains that the Son is eternally begotten rather than physically produced, while the one God eternally exists as Father, Word, and Spirit. ^[13]

Third, he corrected the claim that Christians worship three gods or believe in physical divine generation. The Church confesses one divine nature in three Persons. The eternal Son was begotten from the Father without body, change, or time, then assumed human nature and was born from Mary in history. Rejecting carnal generation does not refute Christianity, because Christianity rejects it too.

Finally, John defended the Crucifixion as inseparable from apostolic testimony. Christ’s Passion had been proclaimed, written, worshipfully commemorated, and defended by martyrs centuries before Islam. A later denial could not erase that foundation. John’s rhetoric is often harsh, and not every historical accusation he makes should be accepted uncritically. His enduring contribution is the theological structure of his defense.

Timothy I and the Mature Christian Response

Around 781 or 782, Timothy I, Catholicos of the Church of the East, debated the Abbasid caliph al-Mahdi in Baghdad. Timothy was not in communion with Rome, but his account is one of the earliest great Christian-Muslim dialogues. ^[14]

When the caliph accused Christians of believing that God physically took a wife, Timothy distinguished Christ’s eternal birth from the Father from His temporal birth from Mary. He defended one God in three Persons through the language of God, His Word, and His Spirit. He also answered the accusation that Christians had corrupted Scripture to remove predictions of Muhammad. Because biblical manuscripts circulated among separated and sometimes hostile Jewish and Christian communities, a universal conspiracy to alter every copy was implausible. If an uncorrupted Gospel naming Muhammad existed, it could be produced.

Timothy remained courteous, accepted truths wherever he found them, and used Qur’anic statements supporting Christ’s virgin birth and holiness. He did not surrender Christian doctrine for social peace. He showed that fidelity and civility could coexist, even when a Christian minority spoke before a powerful Muslim ruler.

Conclusion

Christianity’s first documented encounter with Islam was a sequence of conquest, endurance, and theological clarification. The earliest witnesses heard of a prophet advancing with armed forces. Saint Sophronius watched Bethlehem become inaccessible and Jerusalem pass from Christian rule. Sebeos and John of Nikiu recorded killing, captivity, plunder, taxation, and fear. Christians then learned to preserve their worship under a political order that protected them conditionally while placing them beneath Muslim authority.

Saint John of Damascus formulated the central Christian answer: military success does not prove prophecy; the Trinity is one God, not three; divine Sonship is not physical generation; and no later message can overturn the apostolic testimony to Christ’s divinity, Crucifixion, and Resurrection. Timothy I showed how that faith could be defended calmly in direct dialogue.

The Second Vatican Council teaches Catholics to regard Muslims with esteem and to pursue mutual understanding, justice, peace, and freedom. ^[15] That duty does not require doctrinal relativism or historical amnesia. Muslims must be treated with charity and justice, while the conquests, legal subordination of Christians, and contradiction between Islam and the Gospel must be described truthfully. The first Christians endured because they knew that political defeat could not change who Jesus Christ is.