Islam is the world’s second-largest religion, with about two billion followers worldwide. Although Islam is usually associated with the Middle East, most Muslims don’t live there. The largest Muslim populations are found across Asia, and substantial Muslim communities can be found throughout Africa, Europe, North America, and other parts of the world. Islam was also the fastest-growing major religious tradition between 2010 and 2020.

The word Islam is usually translated as “submission” or “surrender,” referring to submission to the will of God. A follower of Islam is called a Muslim. Like Christianity and Judaism, Islam is monotheistic and traces important parts of its religious history through Abraham. Muslims believe in one God, whom Arabic-speaking Muslims call Allah. It’s worth pointing out that Allah isn’t the name of a different Middle Eastern deity. It’s simply the Arabic word for God and is also used by Arabic-speaking Christians.

But while Christianity and Islam share some vocabulary, people, and history, they understand God and His relationship with humanity very differently. Those differences become particularly important when we get to Jesus.

Muhammad and the Beginning of Islam

Islam arose in Arabia in the seventh century through the preaching of Muhammad. According to Islamic tradition, Muhammad began receiving revelations from God through the angel Gabriel around A.D. 610. Those revelations continued over roughly the next twenty-three years and eventually became the Quran.

Muhammad initially preached in Mecca, where his message encountered considerable opposition. In 622 he and his followers migrated to Medina in an event known as the Hijra. This migration became so important to Islamic history that it marks the beginning of the Islamic calendar.

Muhammad wasn’t simply a religious teacher. In Medina he became the leader of a developing religious and political community. By the time of his death in 632, Islam had become the dominant religious and political force in much of Arabia. Muslim expansion continued rapidly after his death, eventually producing civilizations stretching from Spain and North Africa through the Middle East and into Central and South Asia.

The Quran and Other Islamic Sources

Muslims believe the Quran is the revelation of God given to Muhammad. Muhammad is therefore not considered the author of the Quran in traditional Islam. He is the messenger through whom it was delivered.

The Quran also speaks about figures familiar to readers of the Bible, including Adam, Noah, Abraham, Moses, David, Mary, and Jesus. Muslims generally believe that God revealed earlier scriptures, including the Torah and the Gospel, while regarding the Quran as God’s final authoritative revelation.

The Quran isn’t the only source used to understand Islam. The Hadith are collections of reports concerning the words and actions of Muhammad and play an enormous role in Islamic belief and practice. The Sunnah refers broadly to Muhammad’s example or way of life. Together with the Quran, these traditions became foundational for Islamic theology, ethics, worship, and law.

That distinction is important. If you want to understand what Muslims believe and practice, simply reading the Quran won’t necessarily tell you everything you need to know.

God in Islam

The most fundamental doctrine of Islam is the absolute oneness of God, known as tawhid. The Quran describes God as one, eternal and incomparable, declaring that He neither begets nor is begotten. That immediately creates one of the most important differences between Islam and Christianity.

Christians also believe there is only one God. Christianity, however, teaches that the one God exists eternally as Father, Son, and Holy Spirit. Islam explicitly rejects that understanding of God. The Quran warns Christians not to say “Three” and rejects the idea that God has a Son. So when Christians and Muslims say that they believe in one God, there is genuine common ground at the level of monotheism. But that shouldn’t be confused with agreement about the nature of God. The Trinity and the identity of Jesus create a very substantial theological divide.

The Five Pillars of Islam

Islamic practice is commonly summarized by the Five Pillars of Islam. They provide a useful introduction to what Muslim religious life looks like.

Shahada — Profession of faith. A Muslim professes that there is no god but God and that Muhammad is the messenger of God.

Salat — Prayer. Muslims are called to formal prayer five times each day, facing toward Mecca.

Zakat — Almsgiving. Muslims are obligated to give a portion of their wealth for charitable and religious purposes.

Sawm — Fasting. During the month of Ramadan, Muslims normally abstain from food and drink from dawn until sunset.

Hajj — Pilgrimage. Muslims who are physically and financially able are expected to make a pilgrimage to Mecca at least once in their lifetime.

These practices give Islam a strong rhythm of communal religious life. Islam isn’t simply a set of beliefs about God. It’s a way of life involving worship, family, charity, community, ethics, and religious discipline.

Sunni and Shia Islam

Islam isn’t one completely uniform religious body. Its largest division is between Sunni and Shia Muslims. Sunni Muslims constitute the large majority of Muslims worldwide, while Shia Muslims form the largest minority. Pew has estimated that roughly 87–90% of Muslims are Sunni and about 10–13% are Shia.

The division began with a dispute over leadership after Muhammad’s death. Sunnis accepted the succession of leaders traditionally known as the first four caliphs. Shia Muslims believe that leadership properly belonged through Ali, Muhammad’s cousin and son-in-law, and his descendants.

What began as a dispute about succession eventually developed into broader differences involving religious authority, theology, law, worship, and tradition. There are also subdivisions within both Sunni and Shia Islam, along with smaller Islamic traditions such as Ibadi Islam. It would therefore be a mistake to speak about the beliefs of nearly two billion Muslims as though every Muslim thinks exactly alike. They don’t—any more than every Christian does.

Jesus in Islam

This is where Islam becomes particularly interesting for Christians. Muslims believe in Jesus. The Quran calls Jesus the Messiah and speaks of him as the son of Mary. It gives Mary an honored place and presents Jesus as a messenger of God. The Quran even describes the announcement to Mary that she would bear Jesus, calling him the Messiah and a word from God.

That can initially make Islam sound surprisingly close to Christianity. But the similarities only go so far. Islam rejects the Christian belief that Jesus is the divine Son of God. Jesus is honored as a prophet and Messiah, but he isn’t worshiped as God. The Quran explicitly rejects describing God as “Three” and says that Jesus was a messenger of God.

There is an even greater difference concerning the crucifixion. The Quran says that Jesus’ enemies did not kill or crucify him, although the precise interpretation of the passage has been debated within Islamic interpretation. The dominant Muslim understanding is therefore very different from the Christian proclamation that Jesus was crucified, died, and rose from the dead.

This isn’t a minor disagreement. For Christianity, the death and resurrection of Jesus stand at the center of the gospel. Remove the cross and resurrection and you haven’t simply changed one Christian doctrine—you’ve changed Christianity itself.

Sin, Judgment, and Salvation

Islam teaches that human beings are accountable to God and that there will be a resurrection and final judgment. Paradise and punishment are recurring themes in Islamic teaching.

Islam doesn’t approach the human problem through the Christian doctrine of original sin in the same way historic Christianity does. Human beings are responsible for their own actions and are called to believe, repent, obey God, and do what is right. God’s mercy is enormously important in Islamic thought.

That produces another significant difference between Christianity and Islam. Christianity centers salvation on what God has accomplished through Christ—particularly His death and resurrection. Islam rejects the divine Sonship and crucifixion that stand at the center of that message. Consequently, the two religions aren’t simply offering different religious customs while teaching essentially the same gospel. They understand the human problem and God’s solution to it differently.

Islam and Christianity

Christians and Muslims have several genuine points of contact. Both traditions believe in one Creator, trace religious history through Abraham, believe that God has revealed Himself, affirm moral accountability, believe in angels, resurrection, judgment, and an afterlife, and recognize figures such as Adam, Noah, Abraham, Moses, David, and Jesus.

Those similarities can make conversations between Christians and Muslims easier because we’re not beginning with completely unrelated religious worlds. But the differences are just as important.

Christianity teaches that Jesus is the eternal Son who became human, was crucified, rose bodily from the dead, and provides salvation through what He accomplished. Islam honors Jesus but denies precisely those claims that Christianity places at the center of the gospel. That means the most important Christian-Muslim conversation eventually comes down to a surprisingly familiar question: Who is Jesus? The answer determines much of what follows.

Islam Today

Islam today encompasses an enormous range of cultures, nations, theological traditions, and levels of religious observance. Muslims live everywhere from Indonesia and Pakistan to Nigeria, Iran, Saudi Arabia, Europe, and the United States. The Asia-Pacific region contains more Muslims than any other region, despite the popular tendency in the West to identify Islam primarily with the Middle East.

That diversity is worth remembering whenever Islam comes up in conversation. A secular Muslim living in Europe, a Sunni imam in Egypt, a Shia scholar in Iran, and a Muslim family in Indonesia may share a religious identity while differing considerably in culture, politics, interpretation, and practice.

For Christians who want to understand Islam, the best place to begin isn’t with stereotypes or political arguments. It’s with understanding what Muslims actually believe, why they believe it, and where those beliefs intersect with—and ultimately depart from—the Christian faith.

Understanding those differences doesn’t require hostility. In fact, serious disagreement is one reason careful understanding matters. If we’re going to talk with our Muslim neighbors about Jesus, we should at least take the time to understand the Jesus they already believe in.