As a preface to this article, please see our article on “What is Islam, and what do Muslims believe?” Through the gospel of Jesus Christ, God offers—and true disciples of Jesus have received—that which everyone in the world, including every Muslim, needs and many long for: forgiveness for their sins, a loving heavenly Father with whom they can communicate personally, and assurance that eternal happiness awaits them beyond this life. The key to witnessing to a Muslim is getting him to understand that Islam does not offer these things and that Christianity most certainly does. In fact, Christianity is the only religion that does.
Muslims use much of the same terminology that appears in the Bible: sin, salvation, heaven, hell, one God, law, and punishment. What is missing from their lexicon is the word “savior.” The Muslim does not believe that he needs a savior because he believes he alone must atone for his sin by his works. Islam teaches that man is born sinless and, therefore, does not have a sin nature from which he needs to be saved. His sinlessness was corrupted by external influences and can, therefore, be ‘cleaned up’ by works and efforts that please Allah. The Qur’an tells the Muslim that his good deeds can cancel out his bad deeds (Sura 11:114), but no one knows how many good deeds are enough. Muslims believe they can ask Allah for forgiveness from sins, but Allah may or may not forgive them. There is, therefore (and this is the key), no assurance of salvation for Muslims.
Muslims believe one must be sorry for sin and repent of it, but the idea that payment for sin is required by a holy God is not part of Islam. It’s important to begin with the idea that being sorry for sin will not help the Muslim when he stands before a holy God on Judgment Day. Ask the Muslim if a murderer will be allowed to go free if he says he’s sorry in court. Most Muslims would agree that if the judge is a good man, he must make sure justice is done. Being sorry won’t keep the murderer out of prison. Then ask the Muslim if he believes he will go to heaven. Muslims believe in the Law of Moses, so ask if he has kept each one of the commandments perfectly. Once he admits he has lied at some time in his life or lusted after a woman in his heart, ask him, if an earthly judge can’t pardon a murderer just because he is sorry, how can Allah forgive him when he has just admitted to being a liar and/or an adulterer in his heart. If he’s at all honest, he will admit this is impossible. At this point, you can say that God made it possible for him to go to heaven even though he can’t get there on his own. Preach Jesus Christ as our substitute for sin, our Savior from sins we cannot atone for ourselves, but do not say that He was the Son of God or allude to the Trinity as these ideas are anathema to Muslims.
Again, the key to witnessing to Muslims is their lack of assurance. Islam teaches that Allah was the source of both the Bible and the Qur’an, so they are willing to listen to passages from the Bible. Passages that speak to the wickedness of man’s heart (Psalm 14:1-3; Jeremiah 17:9; Romans 3:9-18), the holiness of God (Exodus 15:11; 1 Samuel 2:2; Joshua 24:19; Psalm 93:5) and His hatred for sin (Deuteronomy 25:16; Proverbs 6:16-19) will drive home the need for a Savior. As long as the Muslim believes he can atone for sin himself, the message of the gospel will be foolishness to him. If he comes to understand that “no one will be declared righteous in his sight by observing the law” (Romans 3:20), the door is open for the light of the gospel to shine in his heart.
Of course, no one comes to the knowledge of the truth solely by good apologetics. The natural man does not accept the things of the Spirit because they are spiritually discerned (2 Corinthians 2:14), and the Holy Spirit is the only one who can open the eyes of the spiritually blind. Therefore, any witnessing efforts should be bathed in prayer that hearts and minds will be opened so that when we speak the truth in love to a Muslim, it may please the Lord to grant him or her salvation through Jesus Christ.