As the central religious text of the Islamic faith, the Qur’an is believed by Muslims to be “the last book of guidance from Allah, sent down to Muhammad (pbuh) through the angel Gabriel (Jibra’il). Every word of the Qur’an is the word of Allah.”
But did the Qur’an truly come from God?
The Qur’an teaches that previous revelation also came from God, including the writings of Moses (2:87; 3:3), David (4:163), and the gospel of Jesus (5:46–48). Elsewhere the Qur’an affirms these previous scriptures (2:91; 3:14, 84; 4:47), asserting that God has protected his revelation in them (5:48; 18:28). It also teaches that “Muhammad is to consult the scriptures already revealed if he is in doubt about what is revealed to him” (10:94–95). Thus, the Qur’an claims to be in perfect harmony with the revelation God gave earlier through Moses, David, and Jesus (2:136).
When confronted with the fact that the Qur’an is at odds with the Old and New Testaments, Muslims contend that it is the Bible that has been corrupted. Hence, it is argued, the Jewish and Christian scriptures have been tainted, not the Qur’an. But there are significant problems with this claim.
For starters, the Qur’an implies that the Old Testament was trustworthy at the time of Mary (66:12), John the Baptist (19:12), Jesus (3:48–50; 5:113; 61:6), and even at the time of its own composition, since it commands Jews and Christians to follow what had been revealed to them in their Scriptures (5:47, 68). The Qur’an also claims that the gospel confirms the truth of the Torah (5:49), and calls Jews and Christians “People of the Scripture” (2:44, 113, 121; 3:78, 79; 5:43; 6:92; 7:157; 10:95).
The Qur’an testifies that its main purpose is to provide a revelation for Arabic speaking people, who could not understand (or did not have access to) the Scriptures of the Jews and Christians (Surah 46:11–12; 41:2–3; 20:112; 39:29; 12:2). There is no suggestion that this new revelation (the Qur’an) was needed to replace any corrupted Scripture. In fact, the Qur’an claimed to be a verification of the earlier revelations such as in the Torah and the Gospel, that went before it (Surah 10:37; 12:111).
The Qur’an thus implies that the Old and New Testaments had not yet been “corrupted” when the Qur’an was completed (in the late sixth or early seventh century).
Moreover, the Qur’an claims “to be the guardian of previous Scriptures, therefore any Muslim who claims that there has been a corruption of the text of the Torah [of Moses] or the Injil [Gospel] also, inevitably, charges the Qur’an with failure in its role in ‘guarding’ them (Surah 5:48).” The Qur’an therefore bears witness to the veracity of the Old and New Testaments, at least as they existed in the sixth century A.D.
The Qur’an says that no one can change the Word of God. If the Jews did corrupt the Word of God then it would mean that the Qur’anic statement is unreliable, a concept that would be blasphemy to Muslims. The only possible conclusion in the light of the Qur’an is therefore that the copies of the pre-Islamic Scriptures (known as the Torah and the Injil) were available in the days of Muhammad as they are available today i.e. that they are valid. Since Christians have ample documentary evidence from before Muhammad’s time, they can confidently assert that their Scriptures are trustworthy.
This, then presents a major problem for those who hold to the inerrant inspiration of the Qur’an. By it’s own admission, the Qur’an must be consistent with previous revelation from God. But it does not take long to see that the Bible and the Qur’an are not compatible. “It should come as no surprise to well-informed Muslims who know that, in the final analysis, the claims of Christianity and Islam are incompatible. This incompatibility is behind the Islamic assumption that, in one way or another, the Bible has been corrupted.” When it is demonstrated that the Bible has not been corrupted, both from textual evidence and from the claims of the Qur’an itself, it is the Qur’an—not the Bible—that is discredited.
In addition to being incompatible with previous revelation from God, the Qur’an contains its own internal contradictions, such as urging religious tolerance in one place (2:256) and then commanding Muslims to fight and kill those who do not believe (9:29; 9:5). In another place (7:54 and 32:4), the Qur’an claims that the earth was made in six days. But in 41:9–12, it teaches that eight days were needed to create the world.
The Qur’an also purports certain scientific inaccuracies, claiming that human beings are formed from a clot of blood (23:14), that the sun rests in a muddy spring in the west (18:86), that mountains were created to hold down the earth and prevent earthquakes (31:10-11; cf. 16:15; 21:31; 78:6-7; 88:17, 19), that there are literally seven heavens (2:29; 17:44; 41:12; 23:17, 86; 67:3; 71:15-16), and that meteors are a form of divine retribution being hurled at devils who might try to spy on the heavenly council (37:6-10; 72:8-9; cf.15:16-18; 67:5; 86:2-3).
The Qur’an contains historical errors as well. As one non-Christian author explains,
At sura 40.38; the Koran mistakenly identifies Haman, who in reality was the minister of the Persian King Ahasuerus (mentioned in the book of Esther), as the minister of the Pharoah [sic] at the time of Moses. We have already noted the confusion of Mary, the mother of Jesus, with the Mary who was the sister of Moses and Aaron. At sura 2.249, 250 there is obviously a confusion between the story of Saul as told therein, and the account of Gideon in Judg. 7.5. The account of Alexander the Great in the Koran (18.82) is hopelessly confused historically; we are certain it was based on the Romance of Alexander. At any rate, the Macedonian was not a Muslim and did not live to an old age, nor was he a contemporary of Abraham, as Muslims contend.
Examples such as these suggest that the Qur’an is not the word of God, in spite of what it claims to be.
If space permitted, we could also consider other religious texts, such as the Hindu Veda or the Book of Mormon. In each case, we would again find that the supposed inspired text falls far short of the Bible. Consider, as just one example, the test of predictive prophecy: “Other books claim divine inspiration, such as the Koran, the Book of Mormon, and parts of the [Hindu] Veda. But none of those books contains predictive prophecy. As a result, fulfilled prophecy is a strong indication of the unique divine authority of the Bible.”
Perhaps the greatest difference between the Bible and all other religious books is that the Bible teaches a message of salvation by grace, whereas every other religious system teaches salvation by human works (Micah 7:18; Eph. 2:4–10; Titus 3:3–7). “All other religions we know of teach salvation by meritorious works. Christianity is the only religion that teaches salvation solely by grace through faith alone.” This again is evidence of the uniqueness of the true God and His true Word, the Bible.
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 Ghulam Sarwar, Islam: A Brief Guide. Cited from Colin Chapman, Cross and Crescent (Downer’s Grove, Ill.: InterVarsity Press, 2003), 84.
 Collin G. Chapman, Cross and Crescent (Downers Grove, Ill.: IVP, 2003), 92.
 For a full discussion on this topic, see Chawkat Moucarry, The Prophet and the Messiah (Downers Grove, Ill.: InterVarsity Press, 2001).
 Steven Masood, The Bible and the Qur’an (Cumbria, UK: Authentic Media, 2002), 70-71.
 Ibid., 72.
 Ibid., 80-81.
 Moucarry, The Prophet and the Messiah, 264.
 For more on this point, see Norman L. Geisler and Abdul Saleeb, Answering Islam (Grand Rapids: Baker Books, 2002), 201-203.
 Ibid, 203-205. Several examples also taken from William Campbell, The Qur’an and the Bible in the Light of History & Science (Middle East Resources, 2002), section 4 chapter 2.
 Ibn Warraq, Why I Am Not a Muslim (Amherst, New York: Prometheus Books, 1995), 158-59.
 Norman L. Geisler and William E. Nix, A General Introduction to the Bible (Chicago: Moody Press, 1986), 196. Cited from Josh McDowell, The New Evidence That Demands a Verdict, 13.
 John Ankerberg and John Weldon, Fast Facts on Defending Your Faith (Eugene, Ore., Harvest House, 2002), 32.