Islam and Christianity: similarities and differences

Both religions see themselves as continuing the faith of Abraham. Christianity grew out of first-century Judaism and accepts the Hebrew Bible as its Old Testament. Islam, which emerged in seventh-century Arabia, teaches that the Quran confirms and completes earlier revelations given to prophets such as Abraham, Moses and Jesus.

Many figures appear in both traditions: Adam, Noah, Abraham, Moses, David, John the Baptist, Mary and Jesus. Both religions teach that God created the world, that humans are accountable for their actions, that there will be a resurrection and a day of judgment, and that prayer, charity and fasting are important.

The central theological difference concerns the nature of God. Most Christians believe in the Trinity: one God in three persons, Father, Son and Holy Spirit.

Islam teaches tawhid, the absolute oneness of God, and the Quran explicitly rejects the idea that God has a son or that God is “three.” Muslims regard the Trinity as incompatible with pure monotheism. Christians, for their part, understand the Trinity as an account of the one God rather than a belief in three gods. This disagreement is the deepest theological line between the two faiths.

Christians believe Jesus is the Son of God, fully divine and fully human, who died by crucifixion and rose from the dead to save humanity from sin. His death and resurrection are the centre of Christian faith.

Muslims honour Jesus, called Isa, as one of the greatest prophets and as the Messiah. The Quran affirms his virgin birth and miracles. However, Islam teaches that Jesus was a human prophet, not divine, and the Quran states that he was not crucified, though Muslim commentators interpret that verse in various ways. Many Muslims believe Jesus was raised to God and will return before the end of time.

Christian scripture is the Bible: the Old Testament and the New Testament. Christians regard it as inspired by God, written by many human authors over centuries.

Muslim scripture is the Quran, believed to be the literal word of God revealed in Arabic to Muhammad over about twenty-three years. Islam teaches that God also gave earlier scriptures, the Torah, the Psalms and the Gospel, but many Muslims believe these were altered or imperfectly preserved over time, while the Quran remains intact. Christians do not accept that their scriptures have been corrupted.

For Muslims, Muhammad is the final prophet and messenger of God, and his example, the sunnah, guides daily life. Christians do not regard Muhammad as a prophet. Christianity teaches that God’s self-revelation reached its fullness in Jesus Christ.

Christianity teaches that sin separates humanity from God and that salvation comes through God’s grace in Jesus Christ, received by faith and, in Catholic and Orthodox teaching, through the life of the Church and its sacraments. Western Christianity commonly teaches original sin inherited from Adam.

Islam teaches that each person is born in a natural state of purity, called fitra, and is responsible for their own deeds. Adam’s sin was forgiven, and no one inherits it. Salvation depends on faith, righteous deeds and, above all, God’s mercy. Islam has no doctrine of atonement through a saviour’s death.

Muslims follow the Five Pillars: the declaration of faith, five daily prayers, almsgiving, fasting in Ramadan and pilgrimage to Mecca. Worship is performed in Arabic, and the mosque is the place of congregational prayer, especially on Friday.

Christian worship centres on Sunday services, prayer, reading scripture and sacraments such as baptism and the Eucharist. Christians pray in every language, and practices such as fasting in Lent vary widely between churches.

Neither religion is uniform. Islam includes Sunni and Shi’a branches, several schools of law and Sufi traditions. Christianity includes Catholic, Orthodox and Protestant churches and many independent communities. Positions described here represent mainstream teaching; individual believers and communities may hold different views.

Relations between Christians and Muslims have included both conflict and long periods of coexistence and exchange. In modern times, many initiatives, such as the 2007 open letter “A Common Word Between Us and You” signed by Muslim scholars, have emphasized shared commitments to love of God and love of neighbour.

Islam and Christianity share Abrahamic roots, belief in one God, prophets, revelation and judgment, and reverence for Jesus and Mary. They differ on the Trinity, the divinity and crucifixion of Jesus, the status of Muhammad, the authority of their scriptures and the way salvation is understood.