Why should we believe that the Quran hasn’t been re-written the way we believe the Bible has?
It is natural to have such thoughts. I have had similar questions and many other difficult ones that no one could answer satisfactorily for me.
Regarding the Quran, comparing it with the Bible is helpful, but we should keep in mind that the two books are not directly comparable. Only the first five books of the Old Testament, what we call the Torah or the Pentateuch, are thought to be inspired by God. These are the books of Genesis, Exodus, Leviticus, Numbers and Deuteronomy. Everything else in the Old Testament and the New Testament is a human record of things that took place; it is more similar to Islam’s hadith literature than to the Quran. Only the Torah is comparable to the Quran, everything else is comparable to hadith.
Even though the Torah is supposed to have been inspired in Moses by God, at its end we have the story of the death of Moses and what takes place after. That is one very obvious clue to the way the Torah was treated by its recipients; they thought they could add things to it if they saw a need for it. That is comparable to Muslims adding the story of the Prophet’s death to the end of the Quran as a new chapter or new verses added to one of the chapters.
The Catholic church believes the Torah has been changed but that its main message has not been lost. Followers of Conservative Judaism (representing a quarter of religious Jews) believe that Torah has been changed and modified but that it is still divinely inspired.
That is the situation with the Bible. An educated and open-minded person who reads it ends up concluding that it has likely been modified in some ways.
The situation with the Quran is completely different. Regardless of how educated and open-minded a believing Muslim is, upon reading the Quran they conclude that it has likely been perfectly transmitted. They do not find anything in it that hints at it being changed or corrupted.
The most important reason that I believe in the Quran has nothing to do with its history. Even if I had found it somewhere and had no idea where it came from or what religion it belonged to, the contents and the design of the book are sufficient to compel me to believe in it as a divine book. The most persuasive argument for the truth of the Quran is not its historicity, it is the aesthetic experience of reading it or listening to it. I can start reading it with the assumption that it was really written by a human or group of humans. But even if you try to build a strong fortress of skepticism while reading it, all that it takes is a few pages and the fortress is completely demolished. One is left with no choice but admit this is from God and that it is a great injustice and insult against God to suggest that it could have been written by a human.
Now, I am aware that since most people do not speak good enough Arabic to experience the Quran in that way, the aesthetic argument for the truth of the Quran will not work for them. You either have to take other people’s words for it or learn good enough Arabic to have the experience yourself. But the fact is that the aesthetic argument is at least half the reason why we believe in the Quran.
An atheist or Christian who comes up with logical arguments for doubting the Quran and thinks logical argumentation is sufficient for judging the book only shows their great ignorance of the nature of the Quran. The word Quran itself means “the Recitation”, the Quran is not a book of philosophy or textbook of law, it is something meant to be experienced, like a symphony. The aesthetic experience of the Quran is probably the strongest argument for its divine origin.
The beauty of the experience of the Quran is similar to any other powerful experience of beauty, such as looking up at the night sky in the desert. The experience by itself wouldn’t have been sufficient to launch a religion. Logic and philosophy are also needed, and the Quran has those too. It is an entirely logical book presented through such an incredibly beautiful symphony that one ends up strongly doubting it could be from a human.
The power of the Quran can even come out in translations, despite much of the beauty being lost in the process. University of Kansas professor Jeffrey Lang tells the story of how he began reading an English translation of the Quran out of curiosity and with a skeptical eye (he was an atheist at the time), thinking it was written by a clever charlatan. He went through an experience that many other converts have gone through. At first they believe the book to be a man-made work. A few pages in, they start to feel surprised that something so intelligent and logical could have come out of 7th century Arabia. Once they reach the middle of the book they are completely captivated by it and cannot put it down. Once they have finished the book, they experience an existential crisis that can last for years. They come close to admitting that there is a 50% chance the Quran is really from the Creator. But they do their best to avoid admitting that the Quran is more likely to be from God than to be from a human, because if that is really the case, if the Quran is even 51% likely to be from God and 49% likely to be from a human, the rational choice is to act according to the stronger probability. And that would mean that they would have to treat the book as if it is really from God, which means that they would have to do as it says and start living as Muslims.
None of the above has anything to do with the Quran’s history. Regardless of how the Quran has come to us, the fact is that it is a powerful and coherent book that compels belief in the one who experiences it fully and sometimes even partly. Regardless of the book’s history, the Quran itself is a very strong argument, a very strong piece of evidence, for its own truth and integrity. A false or corrupted book would be full of red flags to the reader.
As for the Quran’s history: the Quran’s primary form of transmission was not through manuscripts but through oral transmission. This is not surprising since the Quran was designed to be recited. We know that in the early Islamic period (the first two centuries) there was no orthodoxy, people freely discussed ideas and topics that were later considered heretical. The tafsīr of the Persian scholar Muqatil ibn Sulayman (d. 767 CE) was banned in Egypt until recently due to it containing things considered unacceptable to modern Islamic orthodoxy. But at the time he was writing, no one cared to go after him. We have a great deal of evidence in early Islamic sources like the 9-volume Muṣannaf of ʿAbd al-Razzāq al-Ṣanʿānī (d. 826 CE) for the freedom of thought during that time. There was no authority at the time that could change the Quran and get away with it. If anyone tried to change the Quran and pass it on, they would have been noticed and corrected. There were never any councils or conferences of scholars trying to agree on one specific recitation of the Quran, everyone agreed on the same recitations without anyone forcing them. The culture of Islam after the Prophet’s death was such that it was impossible for any authority to force their views on anyone else. Suggesting that Abu Bakr, Umar or Uthman could have forced the Prophet’s remaining 10,000 or so Companions to follow the same corrupted Quran is so implausible as to be laughable. It shows complete ignorance of the political situation of the time, which made these early caliphs quite incapable of forcing any form of religious views on others.
Soon after the Prophet’s death , we had Companions living in Iraq, Egypt, Bahrain and Yemen all reciting the same Quran and teaching it to students who also memorized it and passed it on. It is very unlikely that all of these geographically separated groups could agree on the same corruption of the Quran.
It is, of course, logically possible that some corruptions somehow crept into the Quran. It is just not likely. Similarly, it is possible that aliens built the pyramids in Egypt (we have no proof that aliens did not build them). But just because it is possible does not mean that it is likely. The rational opinion is that it was humans who built them. In the same way, the rational, historically-informed attitude toward the Quran is that it was very well-preserved and not corrupted, unless someone can show us very strong evidence that it was corrupted. But there is no such evidence.
The earliest Quran manuscript we have might be the Birmingham manuscript, which is dated by non-Muslim scholars to have been written in 645 CE at the latest. The Prophet died in 632 CE, so that manuscript was written within about 13 years of his death. The manuscript is only two pages, but the fact that it contains no surprises, that it fully conforms to the Quran we know today, is evidence for the integrity of the Quran. The same applies to every other manuscript that has been found. There are sometimes minor variations, but these could be explained by referring to a scribe’s error, or to a person incorrectly remembering a verse. While to a detractor of Islam such a manuscript would be “proof” that the Quran has been corrupted, a well-informed non-Muslim scholar would be aware that it was oral transmission that determined the text of the Quran, not manuscripts. Manuscripts were only offshoots of the oral tradition and had no authority to overrule it. Manuscripts were merely educational tools meant to make thing easier, but no self-respecting Quran transmitter would have relied on them. The importance of the oral tradition was also true in the field of hadith. A muhaddith (hadith scholar) was a person who studied hadith from memory. Even at the time of Imam al-Ghazali (d. 1111), there was a debate about whether manuscripts could be relied on, the oral tradition was so strong that people considered manuscripts to be mere toys. Even a hadith scholar who relied on manuscripts rather than his memory for transmitting hadith would have been laughed at.
You have every right to doubt the Quran’s authenticity and integrity. But educated people who have studied the matter deeply, especially those who speak good Arabic, know that the rational and logical stance toward the Quran is to assume it is entirely authentic unless someone can prove otherwise, similar to the way we believe the pyramids were built by humans unless someone can prove otherwise.
The situation of the Bible is incomparable to that of the Quran. Most educated Jews and Christians admit that the Torah has not been perfectly preserved, while most educated Muslims believe that the Quran has been perfectly preserved. The situations are complete opposites. This is not because Jews and Christians are more intelligent or open-minded than Muslims. It is because the historical evidence compels one to believe that the Torah has been changed, while the historical evidence compels one to believe that the Quran has not been changed.
Note that I am not saying the Torah has been greatly changed. I believe it is remarkably well-preserved and, like many Jews and Catholics, I believe that the changes made to it have not changed its meaning too significantly. This is not true of the rest of the Bible (the Torah only makes up about 16% of a Christian Bible I looked at). So the idea that the Bible has been “re-written” (as mentioned in your question) does not apply to the Torah, the only part of the Bible directly comparable to the Quran. The Quran itself has a very high opinion of the Torah that the Jews had during the Prophet’s own lifetime:
43. But why do they [the Jews of Medina] come to you for judgment, when they have the Torah, in which is God’s Law? Yet they turn away after that. These are not believers.
44. We have revealed the Torah, wherein is guidance and light. The submissive prophets ruled the Jews according to it, so did the rabbis and the scholars, as they were required to protect God’s Book, and were witnesses to it. So do not fear people, but fear Me. And do not sell My revelations for a cheap price. Those who do not rule according to what God revealed are the unbelievers.
45. And We wrote for them in it: a life for a life, an eye for an eye, a nose for a nose, an ear for an ear, a tooth for a tooth, and an equal wound for a wound; but whoever forgoes it in charity, it will serve as atonement for him. Those who do not rule according to what God revealed are the evildoers.
46. In their footsteps, We sent Jesus son of Mary, fulfilling the Torah that preceded him; and We gave him the Gospel, wherein is guidance and light, and confirming the Torah that preceded him, and guidance and counsel for the righteous. (The Quran, 5:43-46)
The Quran does not tell us that the Torah is so corrupt as to not be worth following for those who believe in it. It says quite the opposite, that it continues to be a valid statement of God’s commandments. The Quran’s attacks against the changers of the Bible is aimed at changes to the rest of it, in which various corruptions were added. The Quran never refers to the Torah as having been greatly changed or corrupted, it refers to changes to al-Kitāb, i.e. the Scripture, not to changes to al-Tawrāt, the Torah, specifically. The Quran continues to refer to the Torah in glowing terms and does not dismiss it.
It appears to me that you have been influenced by uninformed Muslims who attack the Bible without differentiating between its parts. We believe that the only part of the Bible that is directly comparable to the Quran, the Torah, is remarkably well-preserved, and we think of it the way many Jews and Christians think of it: that it is mostly from God and mostly true.
As for corruptions introduced to other parts of the Bible, that is comparable to the corruption of the hadith literature in Islam. The rest of the Bible is a man-made work mostly transmitting the words of people rather than the words of God (just like hadith), therefore it is far more liable to corruption and distortion. But what is said of the non-Torah parts of the Bible should not influence what we think of the Quran, because it is only the Torah that is comparable to the Quran.
The Quran also mentions al-Injīl as a revelation given to Jesus . This word is often translated as the Gospel. But we have no clear knowledge about this book. It may have been a short book that updated certain parts of the Torah and corrected errors that had crept into it. Jesus was meant to be a Jewish follower and reformer of the Torah rather than the founder of a new religion. The Gospels that are currently found in the New Testament are hadith-like human works that narrate the life and deeds of Jesus and may have very little relationship with the Injīl that is supposed to have been given to Jesus. Abdullah Yusuf Ali writes in his Quran translation:
The Injil (Greek, Evangel equals Gospel) spoken of by the Qur'an is not the New Testament. It is not the four Gospels now received as canonical. It is the single Gospel which, Islam teaches, was revealed to Jesus, and which he taught. Fragments of it survive in the received canonical Gospels and in some others, of which traces survive (e.g., the Gospel of Childhood or the Nativity, the Gospel of St.Barnabas, etc.).
The evidence for trusting the Quran’s authenticity is much stronger than the evidence for doubting it. Speaking as a historian, it is logically possible that the Quran may have been corrupted, it is just not very probable if you look into the circumstances of its transmission and the evidence of early manuscripts. The Quran’s beauty and contents compel us to believe in it and the historical evidence supports in that it does not challenge our beliefs. We are therefore acting rationally to believe that the Quran has been unchanged. A person who claims otherwise will have to present us with extraordinarily strong evidence because what they are saying goes against all of the evidence we have.
It is not impossible that 500 years from now evidence will be discovered that strongly challenges our views of the Quran, this is similar to the possibility of discovering, 500 years from now, that aliens really built the pyramids in Egypt. But the rational choice available to us at the moment, that is supported by the evidence we have, is that the Quran has not been changed, and that the pyramids were built by humans. Below is the Quran’s answer to those who attack the Quran (and the Torah) without sufficient evidence:
48. But when the truth came to them from Us, they said, “If only he was given the like of what was given to Moses.” Did they not disbelieve in what was given to Moses in the past? They said, “Two works of magic backing one another.” And they said, “We are disbelieving in both.”
49. Say, “Then bring a scripture from God, more conductive to guidance than both, and I will follow it, if you are truthful.”
50. But if they fail to respond to you, know that they follow their fancies. And who is more lost than him who follows his fancy without guidance from God? God does not guide the unjust people. (The Quran 28:48-50)