Praise be to Allah (The Glorified and Exalted).
1) We say about the Qur'an, "The Almighty has preserved it in the minds and hearts of the Believers." This means through memorization.
Allah (The Glorified and Exalted) sent His revelation during a time period in which the majority of mankind could not read nor write. The revelation of the Qur'an was made light (meaning short in length), and the recitation was made rhythmic and melodious in order to be more easily memorized by vast numbers of people. This was the method of preservation, to be preserved with millions of people, thereby allowing the Book to be easily proof checked because it had been memorized by so many. One must appreciate the ingenious nature of this method, "The Book of the People, Preserved with the People."
Using one's reasoning, an individual understands that if he goes to a masjid in some other part of his city or nation and hears the recitation of the Qur'an, it is understood to be the Qur'an. The most incredible gathering, is around the Kabah in Arabia, Muslims worldwide praying and listening to the revelation of the Qur'an and understanding it, word for word. This is especially easy for a Hafiz (someone that has memorized the entire Qur'an), or at least someone that has spent time memorizing much of the Qur'an because they will be able to understand. For a so called Muslim that has not memorized the entire Qur'an or even spent time memorizing much of the revelation, well the loss is their own. If they cannot tell whether the Qur'an is the same from one city or nation of Muslims to another, this is due to their profound carelessness in refusing to memorize the Revelation. So they ask of others. The argument "the Qur'an is the only
reproducible book from one's memory, if all religious texts had been vanquished from the Earth," is a correct argument. This is due to the large number of individuals that have memorized the Book, therefore it may be proof checked easily.
In modern times, people equate preservation of a document by having a physical source, to feel and touch. This is because access to writing material and literacy is widespread in the modern world. For example, some nations wrote their constitutions on sheep-skin, this is because the material is supposed to last for 1,000 years. Their objective was to make it last for as long as possible.
It is also the case that these sort of documents are written without rhythm or melody, therefore memorization becomes similar to memorizing your history book word for word, sentence for sentence, paragraph for paragraph, page for page, chapter for chapter, an impossible feat.
* Listen to the melodious sound of the Qur'an:
1) When Isa (Jesus) (peace be upon him) left this Earth, he only had around 115 followers and they lived their religious lives in secrecy, fearing persecution and imprisonment from the roman state. Even the learned christians believe this. This would make any preservation of their religion a difficult task. Contrast this situation, with that of the Muslims. After the passing of the Prophet Muhammad (peace and blessings of Allah be upon him), the Muslims controlled all of Arabia and could easily teach and practice their religion, thereby making its preservation easy.
2) The original language the bible was written in was Greek, by Greek writers. Prophet Isa (peace be upon him) was said to have spoken Aramaic or Hebrew. Regardless, his native tongue was not Greek. Greek is not a semetic language. The Prophet Isa (peace be upon him) was a semite from among the Children of Israel and sent to preach to them. The revelation of the Injil (Gospel) would have been sent in the semetic tongue, similar to the Taurat (Torah).
3) The christian bible scholars themselves admit that the bible was composed by over 40 writers from different time periods. None of their names are known, people only conjecture as to who some of them may have been. The learned christians do not believe Prophet Isa (peace be upon him) was given a book of revelation. The bible scholars believe about the bible that it was a book "inspired" by God to be written, to teach the message and history of man, but not literally the "Word of God" because it was "written by the hands of men and may contain errors." It is only the belief of common ignorant christians that the bible is the "Word of God written by Jesus." This is due to their lack of proper religious education, no learned christian believes that.
4) The bible was written hundreds of years after the Prophet Isa (Jesus) (peace be upon him) left the Earth. Similar to previous prophets (peace be upon them), he left no instruction to preserve his book, Injil, by writing.
The bible was written like a history textbook (old and new testament). It is devoid of any rhythm or melody, but reads just as a history textbook. The bible of the catholics is composed of 73 books and the bible of the protestant christians is composed of 66 books. Too many books, too long, too much text, and written like a history textbook, devoid of rhythm and melody. Therefore, making complete memorization word for word exactly, an impossible feat. This is the reason you find no christians having memorized all of the books of their bible.
5) The bible scholars openly admit that there are several versions of the bible. It is no surprise. The protestant christian reformers in europe rejected 7 books of the catholic bible (originally 73). Why, due to revelation? No, of course not, they just felt like it, from their personal opinions, feelings, and beliefs, that 7 books of the catholic bible should be dismissed.
Then these reformists chased after the other 66 books and changed some of their verses and passages also, to fit with their personal opinions of what christian beliefs should be. Therefore, what you have is several different protestant reformist leaders in europe with their own versions of the bible. For example, a famous version of the bible is the "king james version," one written under the command of king james of england, because he thought it would make the different christian groups in england get along better if they had one version of the bible instead of their several various versions, with which they were constantly bickering with each other about.
Well, more christians came to america and more christians groups sprang up, such as: baptist, episcopalian, methodist, jehovah witness, 7th day adventist, mormon, etc. And guess what? More versions of the bible sprang up. After everyone became confused as to which is the real bible, modern americans started printing the "new world version" of the bible, in order to bring christians together under one bible.
It is also important to remember that the bible was originally written in Greek. Translating it into various languages would not have been the same as the original Greek. Everyone knows that when you translate from one language to another, it is not the same. That did not matter to the christians, they eventually replaced the Greek with the English language and started printing bibles off the English language version and ignoring the Greek language. This is the reason why a profound number of ignorant "common christians" believe wrongly, that the bible was originally written in the english language and more incredibly, that the Taurat (Torah) and other revelations as well as the Prophets (peace be upon him) themselves spoke english! They do not know that the English language is only around 800 years old and did not even exist during the time the bible was said to have been written, least of all during the time of any of the Prophets (peace be upon them).
*Take a look at the oldest Greek language bible in the link below. Much of its pages are torn into pieces, candle wax covering other parts, and some pages with the ink faded. This is the reason that modern bibles are actually copied off of the english versions, because the original Greek has been lost to time.
* The following, a video of a former christian man, speaking about his search of the bible and what the priests told him. They are actually truthful when confronted and tell people the bible is a corrupt book:
* One may copy and save this text on a word file, so if any individual asks you about the Qur'an you may answer correctly.
And Allah (The Glorified and Exalted) Knows Best.