Is Islam compatible with Christianity?

Question 60051.

Are Islam and Christianity compatible? The question is asked in several different senses, and a great deal of confusion comes from answering one sense while the questioner meant another. Sometimes it means whether Muslims and Christians can live peaceably as neighbours, which is a social question. Sometimes it means whether the two faiths teach the same essential message, which is a theological one.

On the social question, Islam and Christianity have coexisted in the same street for a very long time, and my answer to the first sense is yes, emphatically, and I have Muslim neighbours whose kindness has often put me to shame. My answer to the second is no, and I want to explain why with the respect that a serious religion deserves. Fudging the differences is not charity. It is a way of implying that neither faith matters enough to be worth getting right.

Islam and Christianity on the nature of God

Both faiths are monotheistic and both affirm that God is one, and it is worth beginning there because the overlap is real. Islam and Christianity both reject the pantheons of the ancient world, both hold that God is the Creator of everything that exists, and both insist that He is not a part of creation.

The disagreement between Islam and Christianity begins with what that oneness means. Islamic theology, governed by the doctrine of tawhid, holds that God is one in an absolutely undifferentiated sense. To associate any partner with God is shirk, the gravest sin in Islam, and the Qur’an explicitly denies that God begets or is begotten. Christianity confesses one God eternally existing in three persons, Father, Son and Holy Spirit, one in essence and distinct in person.

That is not a difference of emphasis. Each position rules the other out by its own logic. From an Islamic standpoint the Trinity is blasphemy. From a Christian standpoint a God who is not triune is not the God who has revealed Himself, since it is precisely as Father, Son and Spirit that He is known. Islam and Christianity cannot both be describing the same God accurately.

There is also a difference in what God is like. The Qur’an gives God many titles of mercy, and Muslims speak with real warmth of divine compassion. What is absent is the specific claim that God is love in His own eternal being, which the New Testament makes at 1 John 4:8. Love requires an object, and a God who is eternally Father, Son and Spirit has loved eternally within Himself.

Islam and Christianity on the identity of Jesus

Islam honours Jesus. That surprises some Christians, and it is worth stating plainly. The Qur’an calls Him the Messiah, affirms His virgin birth, records miracles including raising the dead, and describes Him as a word from God and a spirit from Him. He is regarded as one of the greatest of the prophets and, in Islamic eschatology, He returns.

But the two portraits diverge at every point that matters for salvation. Islam denies that Jesus is the Son of God, which it understands as a claim about physical generation and therefore rejects as offensive. It denies that He is divine. Most significantly, mainstream Islamic teaching denies that He was crucified at all, holding instead that it was made to appear so, and that God took Him up.

That last denial is the sharpest point of the whole discussion. Christianity is not a philosophy that happens to include a crucifixion; it is a message about one. Paul told the Corinthians that if Christ has not been raised our preaching is in vain and we are still in our sins, and there is no resurrection without a death. Remove the cross and the faith does not become simpler, it ceases to exist.

So on the identity of Jesus, Islam and Christianity are not two roads up one mountain. They are two accounts of the same historical figure which contradict each other on who He was and what He did.

Islam and Christianity on how a person is saved

The structural difference between Islam and Christianity here is often missed because both faiths use the language of mercy and forgiveness. In Islam, human beings are not born guilty. Sin is a matter of individual acts, forgetfulness and weakness, and the remedy is submission, repentance and obedience, with God forgiving whom He wills. There is no mediator, no substitute and no assurance until the scales are weighed.

Christianity begins somewhere else entirely. It teaches that sin is a state as well as a series of acts, that we are by nature children of wrath, and that no accumulation of good deeds can address a debt of that kind. Salvation is by grace through faith, not by works, so that no one may boast. See Ephesians 2:8 and 9.

The practical consequence is assurance. A Christian can know, now, that he has passed from death to life, because his standing rests on a finished work outside himself. That certainty is not available within Islamic theology, and in my experience it is one of the things that most often arrests a Muslim enquirer. The offer of a settled verdict is genuinely startling if you have never encountered it.

The Greek word Paul uses for the transaction is hilaskomai and its cognates, the turning aside of wrath by a sacrifice. That category has no equivalent in Islam, because Islam has no atonement.

Contradictory claims about Scripture

On the question of Scripture, Islam and Christianity again begin close and end far apart. Muslims hold that God sent revelation through many prophets, including the Torah given to Moses, the Psalms given to David and the Gospel given to Jesus. The Qur’an at points speaks respectfully of these earlier books. The standard Islamic position is that the texts Jews and Christians now possess have been corrupted, a doctrine known as tahrif, and that the Qur’an is the final and uncorrupted revelation.

That claim runs into a hard historical problem. We possess manuscripts of the New Testament that predate Muhammad by centuries, and complete codices from the fourth century, so if corruption occurred it must have occurred before the Qur’an affirmed those very books. The manuscript evidence is public and enormous, and it shows a text transmitted with remarkable stability. I have set out the detail in whether we can trust the manuscript transmission of the Bible.

This is why the conversation between Islam and Christianity so often reaches an impasse over sources. Each faith’s account of the other’s Scripture is part of its own doctrine, and neither can concede the point without conceding a great deal more.

The question behind the question

When people ask whether Islam and Christianity are compatible, they frequently mean something like this: can a person hold both, or move between them without any real change? The answer is no, and every serious Muslim scholar would agree with me on that, which is worth remembering when Christians are accused of being narrow for saying so.

There is a modern impulse to smooth these things over in the name of harmony, usually by saying that all religions teach the same thing underneath. That is not tolerance; it is a failure to listen. It tells hundreds of millions of devout people that the things they have organised their lives around are decorative. Real respect starts by taking somebody’s beliefs seriously enough to disagree with them.

So I would rather say it plainly. I believe Islam is wrong about the most important questions a human being can ask, and I know that my Muslim friend believes the same about me. We can say that to each other over tea, and we do.

A word about common ground

None of this means there is nothing shared. Both faiths believe in one Creator, in prophets, in scripture, in angels, in moral accountability, in a day of judgement and in life beyond death. In a society that increasingly believes in none of those things, that overlap is more significant than it was fifty years ago, and it gives a place to begin a conversation.

Both traditions also value modesty, hospitality, family and prayer, and Christians who have spent time in Muslim homes often come away rebuked about their own casualness in some of these areas. Acknowledging that costs nothing and is simply honest.

And there are questions on which we can stand together in public life, particularly the freedom to believe and to change one’s belief without penalty. I have written about the difficulties there in whether there is freedom of religion in Islamic lands and about the wider principle in how Baptists defend religious liberty.

Speaking to Muslim friends

Practical counsel, then, for the believer who wants to talk about this. Begin with Jesus rather than with Muhammad, because your friend already honours Jesus and you have common ground to stand on. Read a Gospel together. Luke is often a good choice, since it opens with the annunciation and the virgin birth, which the Qur’an also affirms.

Expect the conversation to arrive quickly at the Trinity and at the crucifixion, and prepare properly for both rather than improvising. Explain that Christians do not believe God took a wife, since that is what many Muslims think we mean by Son of God, and clearing that misunderstanding alone can change the whole tone of a discussion.

Be patient with the cost involved. For many Muslims, following Jesus means losing family, community and sometimes safety. Do not treat a conversion as a debating victory. Treat it as the beginning of a long walk in which the person may need a new family, and the church had better be ready to be one. The study notes on Acts 17 show Paul engaging a very different religious worldview with both courtesy and clarity.

What about the claim that both worship the same God?

This is the question that generates the most heat in evangelical circles, and it deserves a careful answer rather than a slogan. Some argue that since both faiths intend to worship the one Creator God of Abraham, the reference is the same even though the descriptions differ. Others argue that a description this different cannot be picking out the same being at all.

My own view is that the question conceals two separate issues. Referentially, a Muslim is certainly aiming at the God of Abraham and is not worshipping an idol of wood or stone. Relationally and savingly, however, the New Testament is unambiguous: whoever denies the Son does not have the Father, and no one comes to the Father except through Jesus. You cannot have God while refusing the One in whom He has finally spoken.

So I would not say to a Muslim that he worships a different deity in the way a Hindu worships Vishnu. I would say that he is reaching towards the God who has already made Himself known, and that the knowledge he is seeking has been given in a person he has been taught to honour but not to trust.

History, empire and the honest reckoning

Any comparison of Islam and Christianity has to reckon with history, and Christians should not approach that subject with clean hands. The Crusades, the wars of religion, the alliance of church and empire, the treatment of minorities under nominally Christian states: all of that is real and none of it should be minimised when a Muslim friend raises it.

What I would say is that these things are departures from the teaching of Jesus rather than applications of it. He told Peter to put up his sword and said His kingdom was not of this world. When a Christian ruler conquered in the name of the cross he was contradicting the One whose cross it was, and the New Testament supplies the evidence for the prosecution.

That is a different sort of argument from the one Islam has to make about its own early expansion, since the earliest sources present military conquest as part of the prophetic career itself rather than as a betrayal of it. I raise that not to score a point but because the comparison is regularly made in one direction only.

Where the two faiths meet in the last days

One more area of contact between Islam and Christianity is worth a paragraph, because readers of this site will expect it. Islam and Christianity both have a developed eschatology, and both expect a figure of deliverance, a period of tribulation and a final judgement. Islamic tradition looks for the Mahdi, and also for the return of Jesus, who is expected to break the cross and to affirm Islam.

I mention this because it shows how thoroughly the two systems interlock and contradict at the same time. The same figure appears in both accounts of the end, and in one He returns to be worshipped as Lord and in the other He returns to correct the people who worshipped Him. There is no arrangement of these claims in which both are true.

It also explains why I have no interest in date setting or in identifying current political figures with prophetic characters, a habit that has embarrassed the church repeatedly. Jesus told the disciples that it is not for them to know times and seasons, and that instruction has not been withdrawn.

So, now what?

If you are a Christian, resist both errors. Do not pretend that Islam and Christianity are saying the same thing in different accents, because that is untrue and everybody knows it. And do not treat your Muslim neighbour as a threat rather than as a person for whom Jesus died, because that is a failure of the second great commandment and it will close every door you might have walked through.

If you are a Muslim reading this, thank you for getting to the end of an article you will have found provocative in places. I have tried to describe your faith as you would recognise it rather than as a caricature. The one thing I would ask is that you read one of the four Gospels for yourself, in full, and see what you make of the man at the centre of it. Who do you say that He is?

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, ESV

For Further Study

For the theological comparison, Norman Geisler and Abdul Saleeb’s Answering Islam remains a standard evangelical treatment, and Nabeel Qureshi’s Seeking Allah, Finding Jesus gives the argument in autobiographical form from a former Muslim. On the manuscript question, the works of F. F. Bruce and more recent introductions to New Testament textual criticism set out the evidence clearly. Among the systematicians I return to, Millard Erickson’s Christian Theology handles the doctrine of the Trinity and the person of Jesus with care, and Lewis Sperry Chafer’s Systematic Theology is thorough on the atonement, which is precisely where the two faiths part. Charles Ryrie and J. Dwight Pentecost are worth consulting on the place of Israel and the Arab peoples in prophecy, and Arnold Fruchtenbaum handles the descendants of Ishmael in the biblical material with unusual care.