The Book which was revealed during the period spanning 610 CE to 622 CE, remains untampered with today, in its pure and original form.
There are no multiple versions of the Quran, just one single book that has been passed down for ages and is now available all over the world, completely preserved.
The Institute for Koranforschung, in the University of Munich (Germany), collected over 42,000 complete or incomplete ancient copies of the Qur’an. After around fifty years of research, they reported that there was no variance between the various copies, except the occasional mistakes of the copyist which could easily be ascertained.
Ancient manuscripts from all periods of Islamic history found in the Library of Congress in Washington, the Chester Beatty Museum in Dublin (Ireland) and the London Museum have been compared with those in Tashkent, Turkey (which was a copy sent by Caliph Uthman, the Prophet Muhammad’s companion) and Egypt (early manuscript on gazelle parchment in Dar al-Kutub as-Sultaniyyah), with results confirming that there have not been any changes in the text from its original time of writing.
God has promised in the Qur’an :
"We have, without doubt, sent down the Message; and We will assuredly Guard it (from corruption). [Al-Qur’an 15:9]
The promise of the Author has not been broken, the Quran remains true to its word. Therefore, the text of the Quran is a reliable document.
It is beyond argumentation that the other revealed books such as the Bible and Torah have been altered and have several different versions; making the Quran the only reliable source of Divine Guidance.

The fact that Muhammad could neither read nor write (Q.29:48) is well known and uncontested by even his non-Muslim contemporaries and present day historians. He had no schooling or teacher of any kind. He had never been known to compose oral poetry or prose. The Qur’an, with its all-embracing laws and freedom from all inconsistencies, has its greatness acknowledged even by non-Muslim scholars. Its contents treat social, economic, political and religious legislation, history, views of the universe, living things, thought, human transactions, war, peace, marriage, worship, business, and everything relating to life – with no contradicting principles. The Qur’an has never been edited or revised as it was never in need of any revision or correction. How were such vast subject areas expounded upon with such precision by a 7th century Arab with no formal education or even the ability to read what scant material there may have been in his environment on such topics? Where and when has history ever produced an illiterate and uneducated author of such a scripture?

Within the Qur’an are recorded facts about ancient times that were unknown to Muhammad’s contemporaries and even to historians in the first half of the 20th century. In scores of verses, we also find references to scientific wonders, some only recently discovered or confirmed, regarding the universe, biology, embryology, astronomy, physics, geography, meteorology, medicine, history, oceanography, etc.
Some examples:
– The expanding universe (Qur’an 51:47)
By studying the galactic spectrum, scientists have recently established that the universe is expanding. In the Qur’an (51:47), we read: “The firmament, We have built it with power. Verily, We are expanding it.” The word “samaa‘a” means firmament or heaven in the sense of the extra-terrestrial world, and the word “musi‘un” is the present plural participle of the verb “awsa‘a”, which means “to widen, to extend, to expand.” This fact is confirmed in Stephen Hawking’s classic book “A Brief History of Time” [62].
– The Qur’anic description of the development of the human embryo
The Qur’an (23:12-14) describes the development of the embryo at a microscopic level inside the womb in the following manner: “Man We did fashion from a quintessence of clay. Then We placed him as (a drop of) seminal fluid in a place of rest firmly fixed. Then We fashioned the seminal fluid into a leech-like thing that clings (the word “alaq” is sometimes incorrectly translated as a blood-clot). Then We fashioned that leech-like thing that clings into a chewed-like lump. Then We fashioned the chewed-like lump into bones and We clothed the bones with flesh. Then We developed out of it another creature. So hallowed be Allah, the Best of Artisans”; Q.96:1-2: “…who fashioned man from a leech-like thing that clings”; and Q.22:5: “We fashioned you out of dust, then out of a drop of fluid, then out of a leech-like thing that clings, then out of a morsel of flesh – partly formed and partly unformed…” The incredible accuracy of these descriptions of the various stages of embryonic development are confirmed in Keith Moore and T.V.N. Presaud’s 5th edition textbook “The Developing Human” and others.
- Creation of the universe from hot smoke
Scientists today are able to observe the formation of stars from a hot gas cloud. Formation from a warm mass of gas also applies to the creation of the universe. The creation of the universe as described in the Qur’an confirms this scientific discovery in the following verse:
He placed firmly embedded mountains on it, towering over it, and blessed it and measured out its nourishment in it, laid out for those who seek it-all in four days. Then He turned to heaven when it was SMOKE and said to it and to the earth, "Come willingly or unwillingly." They both said, "We come willingly." (Qur’an, 41:10-11)
More examples can be found here: http://www.miraclesofthequran.com/scientific_index.html
The presence of such information in the Quran proves that it could not be written by a man at that time, for he posessed no such knowledge.

The claim that the Quran is unique and no one can produce anything like it is a logical fallacy.
All books are unique. Each person is different and unique. You can’t find two people alike. No two finger prints are alike, no two voices are alike, no two minds are alike, etc. No one can think and write in the exact same way that I do just as no one can think and write in the exact same way that you do. Of course many people can write much better than me, but not like it. So the challenge to produce a sura like those written by Muhammad is nothing but a fallacy.
If the challenge was to produce a sura as beautiful as those in the Quran, it still would have been a fallacy. Aesthetic is subjective and it cannot be a measure of truth. If you tell me find a woman as beautiful as the one I love, this challenge can’t be met because you love only that woman. She may not be the prettiest, but because you love her, you become blind to her defects. Beauty is in the eyes of beholder.
You read the Quran as a believer and remain in awe. You can’t see any errors in it because you are in love with it. I read the same book and find many errors in it. To me it is a tedious and an ugly book. Now you can say the translations are not good but the original in Arabic is very beautiful. Let us agree wit this assumption for now. The fact remains that a non-Arab speaking person cannot see that beauty. It is not the fault of people for being born non-Arabs, but because of this, they are deprived seeing the "beauty" of the Quran. One can conclude that God has been extremely unfair to billions of non-Arabs. They can’t see the beauty of the Quran because they do not speak Arabic and consequently will go to hell. Is this justice? To add insult to injury God chooses a language that according to Muslims is impossible to translate in any other language and therefore we can’t even see the beauty of his work in translation. Is it our fault for being born non-Arabs? Certainly not! God made us non-Arabs and thus deprived us of seeing the beauty of his word and now he wants to burn us for eternity for failing to see what he deprived us to see. What kind of justice is this? It is like I tell you something in a language that you do not understand and then punish you for not understanding what I told you. This is just absurd.
The next problem with Muhammad’s challenge is that it is not sincere. Look what he said right after he issued that challenge:
"But if ye cannot – and of a surety ye cannot – then fear the Fire whose fuel is men and stones,- which is prepared for those who reject Faith". Qur’an 2.24
This is like someone saying give a speech as eloquent as mine and if you cannot – and of a surety you cannot – I will shoot you. With that kind of clause who dares to talk? Forget about the punishment of Allah, Muslims will behead any person who tries to meet this challenge.
We recall Saddam Hussein used to hold “elections” where 99.98% of the population used to voted for him. The elections were held open. The question was: Do you want Saddam? Yes or No? If you responded "No" then you could be killed. This Challenge of the Quran is very much similar to Saddam’s elections. In fact Muhammad was no different from Saddam. He was a narcissist, like Hitler, Saddam, Idi Amin, Kim Jong-il or Stalin. All these monsters created personality cults around themselves and were loved by their foolhardy subjects. Muhammad had also claimed to be the messenger of God. As such he can also be compared to Shoko Asahara, Jim Jones and David Koresh.
However, there are some Arab-speaking non Muslims who say the Quran fails in grammar and aesthetic and they have produced several suras to meet this challenge. These suras are in comparison superior to the suras of the Quran (not my opinion, but the opinion of Arab ex-Muslims). I can see the content of these suras are better than those of Muhammad. Please take a look and tell me why you think the Suras of the Quran are superior to these.
www.islam-exposed.org
http://suralikeit.com/
If you can’t, the challenge is met. The burden of proof is on you