The Foundational Problem with Islam
The veracity of Islam hinges on the veracity of its signature holy book, and "miracle," The Koran. The veracity of the Koran hinges on the veracity of other holy books that came before it and are mentioned in the Koran.
Many a first time reader of the Koran will be surprised that it mentions, and speaks highly of, books of the Bible. Indeed, Muhammad's prophethood rests on the veracity of the previous holy books, messengers, and the truth they brought. "Say: 'I am no bringer of new-fangled doctrine among the messengers, nor do I know what will be done with me or with you. I follow but that which is revealed to me by inspiration; I am but a Warner open and clear'" (Chapter 46:9).
References to the Zabur (Psalms), Taurat (Torah/Law), and the Injeel (Gospels) are found throughout the Koran. References to simply the "book" are found as well. Surah 5 is where the Koran gets most specific with regards to Jews, Christians, and their scriptures. It says, "And We sent after them in their footsteps Isa, son of Marium, verifying what was before him of the Taurat and We gave him the Injeel in which was guidance and light, and verifying what was before it of Taurat and a guidance and an admonition for those who guard [against evil]" (verse 46).
The Koran says here that Isa/Jesus was sent to confirm the previous scriptures and to bring forth the "good news"--the gospel/injeel. Later still in Surah 5, it says, "Say: O followers of the Book! you follow no good till you keep up the Taurat and the Injeel and that which is revealed to you from your Lord; and surely that which has been revealed to you from your Lord shall make many of them increase in inordinacy and unbelief; grieve not therefore for the unbelieving people" (verse 68).
The Bible is legitimate, and the Koran commands Jews as well as Christians to follow it. That seems to be what this chapter, and the whole Koran, teaches, at least on the face of it.
The problem arises when one reads both books and sees that they contradict each other. The Koran is the younger book and rests its authority on it confirming the older book. If there is contradiction, then the Koran is in error.
However... as with all cults that are parasites of the Christian Faith, here enters the charge that the Bible is corrupted. This is a charge that is not organic to the Koran, but is born out of Islamic apologetic necessity. It is internally inconsistent and it flies against history.
First, Jesus could not preach and teach from a corrupted Torah and still be a true prophet. He did not. The Torah he had during his earthly ministry is the same one present in Muhammad's day and it is the same one that is present today. Several biblical manuscripts from before the first century A.C.E., including the Dead Sea Scrolls, confirm that the Torah (indeed the entire Hebrew Bible) Jesus taught from was and is authentic.
The message of Muhammad takes place in real time, with real events, and with real people. The Koran is supposed to be a holy book in heaven, recited from the angel Gabriel to Muhammad and then recited from Muhammad to the world. Muhammad recited these words in the 6th and 7th centuries. If the Bibles that Jews and Christians had then were already corrupted, this command would have been worse than meaningless. It would have lead to damnable confusion.
6th and 7th century Bibles contain ideas and teachings that flatly fly against Islam. Jews and Christians at this time did not have the ad hoc apologetic modern Muslims have now that allows them to disregard the Bible. They would have listened to the words of Muhammad and sinned.
The whole crux of the issue rests on the if the Bible is corrupt or not. Please dear reader, take the time to ponder the issue and research it. We submit as Jesus clearly taught, "Scripture cannot be broken" (John 10:35). Consequently, since it contradicts the Koran, the Koran is not the word of God.