What is Islam?
Question 60012
Islam is the world’s second-largest religion, with nearly two billion adherents. It is also the religion that most frequently presents itself as compatible with, or even the fulfilment of, biblical faith. For this reason, Christians need to understand what Islam actually teaches, where it genuinely overlaps with Christianity, and where it fundamentally diverges. The differences are not minor. They go to the heart of who God is, who Jesus is, and how sinful human beings can be reconciled to their Creator.
Origins and History
Islam was founded by Muhammad ibn Abdullah (c. AD 570-632) in the Arabian Peninsula. According to Islamic tradition, Muhammad received revelations from God (Allah) through the angel Gabriel (Jibril) beginning around AD 610. These revelations were later compiled into the Qur’an, which Muslims regard as the final, perfect, and unalterable word of God. Muhammad is considered the last and greatest of the prophets, the “seal of the prophets” (Khatam an-Nabiyyin), succeeding a line that includes Abraham, Moses, David, and Jesus, all of whom Islam claims as Muslim prophets.
After Muhammad’s death in AD 632, Islam expanded rapidly across the Middle East, North Africa, Persia, and beyond. The religion split into its two main branches, Sunni and Shia, over a succession dispute following Muhammad’s death. Sunni Islam, comprising roughly 85-90% of all Muslims, follows the elected caliphs as Muhammad’s successors. Shia Islam holds that leadership should have passed through Muhammad’s family line, beginning with his cousin and son-in-law Ali. This division persists to the present day and has shaped the political and religious landscape of the Muslim world profoundly.
Core Beliefs
Islam rests on several foundational doctrines. Tawhid, the absolute oneness of God, is the central theological claim. Allah is one, without partners, without a son, and without any division in his being. The Trinity is explicitly rejected in the Qur’an (Surah 4:171; 5:73). The Qur’an is regarded as the literal, uncreated word of God, dictated verbatim to Muhammad, and considered superior to all previous scriptures. Muslims believe in angels, in the prophets, in the revealed books (though they hold that the Torah and the Gospels have been corrupted, a doctrine known as tahrif), in the Day of Judgement, and in divine predestination (qadar).
Islamic practice is structured around the Five Pillars: the shahada (declaration of faith: “There is no god but Allah, and Muhammad is his messenger”), salat (five daily prayers), zakat (almsgiving), sawm (fasting during Ramadan), and hajj (pilgrimage to Mecca). Salvation in Islam is not by grace through faith but by the mercy of Allah combined with the accumulated weight of a person’s deeds. On the Day of Judgement, each person’s good and bad deeds are weighed, and Allah decides their eternal destiny. There is no assurance of salvation in Islam, except for those who die in jihad (understood in this context as armed struggle for the faith).
Where Islam Contradicts the Bible
The differences between Islam and Christianity are not peripheral disagreements that can be smoothed over by goodwill. They are contradictions at the most fundamental level of theology.
On the nature of God: Islam denies the Trinity absolutely. The Qur’an states, “Say not ‘Three'” (Surah 4:171) and condemns as shirk (the unforgivable sin of associating partners with God) any suggestion that God has a Son or exists as a triune being. Christianity confesses the Father, Son, and Holy Spirit as three distinct persons sharing one divine essence. These two positions cannot both be true.
On the person of Jesus: Islam honours Jesus (Isa) as a prophet, born of a virgin, a miracle-worker, and the Messiah. But it denies His deity categorically. The Qur’an states, “Christ Jesus the son of Mary was no more than a messenger of Allah” (Surah 4:171). It also denies the crucifixion, claiming that Jesus was not killed or crucified but that “so it was made to appear to them” (Surah 4:157). If Christ was not crucified, there is no atonement. If there is no atonement, the entire gospel collapses. This is not a minor disagreement. It is the denial of the event on which the whole of Christianity stands.
On salvation: Islam teaches that human beings are not born in sin but are born in a state of natural purity (fitrah). There is no concept of a fallen nature requiring redemption. Salvation is earned through submission, obedience, and the mercy of Allah, not through the substitutionary death of a saviour. The Christian gospel is that no human being can earn right standing before God, that all have sinned (Romans 3:23), and that salvation is by grace alone through faith alone in Christ alone (Ephesians 2:8-9). These two systems of salvation are irreconcilable.
On Scripture: Islam claims that the Bible has been corrupted (tahrif) and that the Qur’an is the final, corrective revelation. The manuscript evidence for the New Testament is overwhelmingly strong, with over 5,800 Greek manuscripts attesting to its textual integrity. The claim of corruption is an assertion without evidence, made necessary by the fact that the Qur’an contradicts the Bible on matters the Bible addresses with clarity.
So, now what?
Christians should engage with Muslims with genuine respect for their sincerity and devotion, while being absolutely clear that Islam and Christianity do not worship the same God in any theologically meaningful sense. The God of the Bible is Father, Son, and Holy Spirit. The God of the Qur’an is explicitly not. Love for Muslim people requires honesty about these differences, not the pretence that they do not exist. The gospel invitation extends to every human being, including every Muslim, and it remains the same: “Believe in the Lord Jesus, and you will be saved” (Acts 16:31).
“Jesus said to him, ‘I am the way, and the truth, and the life. No one comes to the Father except through me.'” John 14:6
