A man’s words?
Although it has been proven that the text of the Quran has remained the same to this day, how can we be sure that the words are actually from God and not from any other source? This question lets us look at the credibility, authorship, or source of the Quran.
As for the authorship of the Qur’an, Muslims believe that it has been revealed verbatim (ie, word for word) from God to Muhammad, may God praise him. Non-Muslims, who mostly do not share this view, cannot contradict the Muslims in the fact that the Quran is at least testified that it was first pronounced by Muhammad, an Arab from Mecca in the 7th century AD, and as proven no changes have been made to the traditions since then.
Muslims speak of an “internal proof” of the divine authorship of the Quran, ie based on the findings in the Quran itself (e.g. Quran 4:82; 6:19; 6:92; 27: 6; 45: 2, etc.), Understandably, this is viewed with skepticism, since just about anyone could quote passages from his or her scriptures that claim that the scripture in question was revealed by God. We are therefore, for reason and objectivity, forced to look elsewhere for „external evidence“ for the divine source or authorship of the Quran.
The simple, suggested way to present this “outside evidence” consists of an elimination process in which we get the answer to the question: – „Who is the author of the Quran?“ – enumerating, evaluating and deleting all alternatives what is out of the question. In other words, the definitive or most likely author or source of the Quran is identified by eliminating any inappropriate alternative candidates.
There are various conflicting views and opinions that some non-Muslims have about the source of the Quran. The following list of “possible” authors reflects their main theories:
2) Some other Arab poets, scholars, etc.
3) Some non-Arab scholars or poets or religious figures.
4) Monks or Rabbis (ie from the Bible or Judeo-Christian sources).
5) Satan (or other insidious “ghosts” or “extraterrestrials” etc.).
6) God. Now we can proceed with a closer study of the Qur’an and history to examine how plausible these theories are.
Muhammad: Illiterate and uneducated
The fact that Muhammad could neither read nor write (Quran 29:48) is well known and is undisputed even by his non-Muslim contemporaries and current historians. He hadn’t attended school and had no teacher. He had never been known to write poetry or prose. Even the non-Muslim scholars have recognized the greatness of the Qur’an, with its all-encompassing laws and freedom from any irregularities.  Its content deals with social, economic, political and religious legislation, history, views about the universe, about living things, thoughts, interpersonal relationships, war, peace, marriage, worship, business and everything that belongs to life – without any contradictions! The Quran was never published or revised because it never needed any revision or correction. How could such a wide range of subjects be explained with such precision by an Arab from the seventh century without any prior training or at least the ability to read; what meager materials may there have been around such topics in his environment? When and where in history has an illiterate and uneducated author of such a script? what meager materials may there have been around such topics in his environment? When and where in history has an illiterate and uneducated author of such a script? what meager materials may there have been around such topics in his environment? When and where in history has an illiterate and uneducated author of such a script?
Muhammad’s Well-Known Sincerity
Muhammad’s seriousness, honesty and sincerity were so well known that people in pre-Islamic society even called him „Al-Amien“ (the trustworthy). Not a single lie has been reported by him, and many modern orientalists have admitted that the Prophet, contrary to any deliberate misleading, had a profound sincere belief that the Qur’an was undeniably revealed to him by God Himself. 
If his sincerity should be questioned, and if his motivation to write the Quran is suspected, was the desire for personal glory, why should he claim that he was not the author, but that it was God, especially when the idolaters of Mecca admitted that no one can write such a scripture (Quran 2: 23-24, 17:88, etc.), but only wonder about it? His enemies even offered him to become king in Mecca, as well as all wealth just so that he should stop reciting the Quran. If it were true that he only wanted glory and leadership, why did he decline the offer when it was made and instead live a life of humility, simplicity, persecution,
Furthermore, how reasonable is it to say that Muhammad, who was unable to read and write, wrote the Quran for his own personal benefit and then improved and rebuked himself in it? For example:
„He frowned and turned away when the blind man came to him …“ (Quran 80: 1-2)
„… and you feared people while it is God you in reality you should fear. ” (Quran 33:37)
There are other verses to refer to, such as in Chapter 18, Verses 23-24, and others. Why should he be embarrassed if he could have simply left out such verses in the Quran or changed them in his favor? They would certainly not have been beneficial to him if he had sought power and prestige. The existence of such verses proves that Muhammad was indeed an honest and serious servant of God!
 See: Fredrick Denny, Islam, NY: Harper & Row, 1987, p.88; Dr. Maurice Bucaille, The Bible, the Quran and Science, Indianapolis: American Trust Publications, 1983, p.163; and HAR Gibb, Wither Islam, NY: AMS Press, 1932, p.350; Etc.
 See for example: HAR Gibb, Mohammedanism, London: Oxford University Press, 1962, p.25
The words of a poet or a teacher?
The Style of the Quran
There is a world-wide difference between the style of the Quran and Muhammad’s own style, as reported in the books of the Hadith. The differences in every aspect between the two – in terms of style and content – are quite obvious. The statements of Muhammad (Hadith) are entertaining, oratorical and explanatory, of a kind that the Arabs were already used to. In contrast, the style of the Quran is commanding:
„We created the heavens and the earth …“ (Quran 15:85, 44:38, 46: 3, 50:38)
„Speak! …“ 
„… If he (the Qur’an) were from someone other than God, they would surely find much contradiction in it.“ (Quran 4:82)
“… Say:“ Bring out a chapter of the same kind and call out who you can except God if you are truthful. ”“ (Quran 10:38)
“… bring it but bring up a chapter of the same kind… And if you don’t – and you certainly won’t do it, then… ”(Quran 2: 23-24)
What fallible human being would write a book and then ask mankind to seek contradictions in it, as the Quran writer did (Quran 4:82)? After writing an exam, would any student add a footnote to the reader that reads “Read my answers carefully and look for any contradictions or errors if you can? The style of the Quran is simply that of the Omniscient Creator.
Furthermore, the Quran is a literary masterpiece of Arabic language, the expression of which was and is unmatched. His rhythmic style, the rhymes, the impressive depth of his expression, his majesty and the „inimitable symphony, the special sounds that move people to tears and enthusiasm“  shook the foundations of a society that is extremely proud of its own speaking skills. Every year competitions were held in Mecca to see who could recite the longest and most eloquent pieces from the head. When the Quran was revealed, the competitions stopped because there was no longer a challenge.
Like the miracle of Moses‘ stick, which turned into a real snake and surpassed the ability of all wizards at a time when the Egyptians were famous for their masterful magic and witchcraft; and like the miracle of Jesus, which healed the blind and brought the dead to life, surpassed the abilities of all doctors at a time when the Jews were famous for their medical abilities, so the Quran was Muhammad’s own miracle.  How could such great and unchallenged expressions come from a man who had never been known for such a skill for 40 years?
Similarities and differences between the Quran and the Bible
The mere existence of similarities between two books is not enough to prove that one copied from the other. Both may have received information from a third party, which is responsible for some similarities in them. Indeed, this is the Quran’s argument that God is the source of all authentic revelations (Quran 4:47).
Some scholars have noted that the only Christians reported to have met the Prophet, may God praise him personally, before his call, did not spend enough time teaching him their scriptures, and none another historical source mentioned anyone who may have taught the prophet about the Jews and Christians.  In addition, the Arabs of his time were very eager to put him in bad repute. Therefore, if there had been any secret teacher, they would most likely have been exposed.
Could the Quran also have been copied from the Bible when there are serious differences in belief? In terms of doctrines such as the concept of God and prophecy, sin and forgiveness, the Quran differs significantly from the Bible. The Quran addresses Jews and Christians directly when it denounces the falsification in their own scriptures. Interestingly, the revelations about the problems in the doctrine of Christianity were largely revealed in the Meccan period before the Prophet’s emigration to Medina, where he encountered many more Jewish and Christian scholars.
Even when it comes to the narratives that appear in both writings, there are significant differences. For example:
– the Quran does not blame women for the mistake Adam and Eve (may God praise him) make when they disobeyed God in the Garden of Eden. (Compare Genesis 3: 12-17 to Quran 91: 7-8 and 2: 35-37);
– the Quran emphasizes that Adam and Eve repented before God (Quran 7:23) and they were forgiven by God (Quran 2:37);
– The Quran mentions that Adam and Eve’s subsequent stay on Earth was God’s plan before He created them (Quran 2:30) and not a form of punishment (Genesis 3: 17-19).
There are other clear deviations in the stories of Solomon , Abraham , Ismael and Isaac, Lot, Noah , Moses and Jesus  (may God praise them all).
The Quran also mentions a great deal of historical information about which the Bible is completely silent. From which part of the Bible was the following copied?
The stories of the peoples of ´Ad and Thamud and their prophets Hud and Salih.
The dialogue between the prophet Noah and his son before the flood (Quran 11:42:43).
The dialogue between Abraham and his father (Quran 6:74), as well as that between him and a king (Quran 2: 258) and between him and his people (Quran 22: 70-102; 29: 16-18; 37: 83-98; 21:57).
The mention of the city of Iram (Quran 89: 7).
The Exodus pharaoh drowned and his body was preserved as a sign for the peoples of the generations to come (Quran 10: 90-92).
The miracles of Jesus that he spoke in the cradle (Quran 3:46), that he made a clay bird and brought it to life (by the will of God), etc.
For further examples, see the following passages in the Quran : 21:69, 2: 260 and 3:37.
 This is mentioned in so many places in the Quran that it would be too much to mention here. See Quran chapter 112, 113, 114 for example. (E).
 Marmaduke Pickthall, The Meaning of the Glorious Quran, New York: The Muslim World League, 1977, S.vii.
 Sahieh Al-Bukhari Vol.6, Hadith No.504; Sahieh Muslim Vol.1, Hadith No.283.
 Bilal Philips, Usool at-Tafseer, Sharjah: Dar al-Fatah, 1997, pp. 127-128.
 The Quran firmly rejects the fact that this idol should have worshiped. – Compare Quran 2: 102 to 1 Kings 11: 4.
 The Quran describes that God’s command to sacrifice his son was in a dream, and the son as a willing participant, before he was saved by God’s intervention; while the Bible claims that God spoke directly to him and that his son was not privy to the plans – compare Quran 37: 99-111 to Genesis 22: 1-19.
 The Bible describes that the Great Flood covered the entire earth, while the Quran describes the flood only as a local phenomenon, a description that more closely matches the scientific evidence – compare Quran 25:37 to Genesis 7: 23.
 A critical difference is that the Quran insists that Jesus has never really been crucified.
Was it Satan’s or God’s?
The Qur’anic Teachings on Satan and Morality
Some claim that the Qur’an was the work of the devil.  Let’s examine how much sense (or nonsense) this claim makes.
If he had written or whispered the Quran, why should Satan curse himself and call him the worst enemy of man (Q.35: 6; 36:60)? Why should Satan command that before reciting the Qur’an you should first say,
„… I seek refuge with God from Satan the Cursed.“ (Quran 16:98)
How could Satan curse himself so vehemently? Is it really reasonable to assume that Satan calls people for good, to be modest and righteous, to worship nobody but God, not to follow the footsteps or whisperings of Satan, and to avoid or eliminate the bad?
This idea clearly contradicts all reason, because if he were the author, he would only undermine himself with these means. Even the Bible states:
„If Satan now rises against himself and is at odds with himself, he cannot exist, but it is over with him.“ (Mark 3:26) 
This argument refers to any “satanic force”, be it “evil spirits”, “insidious aliens”, or the like.
Scientific information and facts in the Quran
The Quran describes facts from ancient times that were not known to Muhammad’s contemporaries and not to historians of the first half of the 20th century. In numerous verses we find references to scientific miracles, some of which have only recently been discovered or proven, regarding the universe, biology, embryology, astronomy, physics, geography, meteorology, medicine, history, oceanography, etc. Below are some examples of scientific discoveries listed in the Quran:
· The Lost City of Iram. (Quran 89: 7)
Working bees are female. (Quran 16:68)
Mountains as “stakes” and stabilization. (Quran 78: 6-7)
The spherical shape of the earth. (Quran 7:54; 36:37; 31:29)
The expansion of the universe. (Quran 51:47)
The “Big Bang”. (Quran 21:30)
· At one point, the entire universe was nothing but a cloud of smoke. (Quran 41:11)
The Quranic description of human embryonic development. (Quran 23: 12-14)
Readers who are interested in further examples are recommended to read the following books. „Bible, Quran and Science“ by Maurice Bucaille.  “Struggling to Surrender” pp. 33-38, by Jeffery Lang , “The Quranic Phenomenon” by Malik Bennabi , “The Developing Human”, 3rd edition, by Keith L. Moore , “Ein short illustrated guide to understanding Islam ”, by IA Ibrahim ,“ The Sources of the Quran ”by Hamza Mustapha Njozi ,“ The Basis of Muslim Beliefs ” and“ The Amazing Quran ”by Gary Miller , etc.
How many well-trained, modern scientists and geniuses were required to discover the scientific facts mentioned in the Quran with the help of high-tech equipment, satellites, telescopes, microscopes and computers – and for how long? Is it even remotely imaginable that any human being should have written a script 1,400 years ago that contains precisely this information – let alone a person who was completely uneducated?
Despite man’s inability to grasp all of the mysteries and complexities of creation mentioned in the Qur’an (67: 3-4), the revelation seems to indicate numerous natural phenomena as if it were asking people to investigate what has been said and to confirm it – and again with a self-evident conviction that one can only conclude that the author actually wants to challenge our ignorance. From generosity to the skeptics, it could be said that it was nothing more than a guess or coincidence that one or two of the scientific revelations were true, but how likely could all be true?
If we compare the findings of the Quran about the physical universe with certain scientific findings, we can discover fundamental similarities. But what is even more remarkable is what Dr. Maurice Bucaille observed: the Qur’an differs from all other ancient works that describe or try to describe the relationships between nature in that they prevent erroneous concepts. Because of the many topics to which the Quran refers and which have been „checked“ by modern science, none contradicts current science. 
Dr. Bucaille goes so far as to complete his studies with the following remark:
“In view of the state of knowledge in the days of Muhammad, it is inconceivable that the numerous statements in the Qur’an that are connected with scientific knowledge should be the work of a person. Furthermore, it is absolutely legitimate to consider the Quran both as an expression of revelation and to give it a special position due to the guarantee of authenticity that it holds and the presence of scientific explanations, which, when reviewed today, look like one Challenges appear to be explained in human terms. ”
When examining the possible source of the Quran, we came to the following conclusions:
Muhammad was unfamiliar with reading and writing.
The style of the Quran.
Differences between the Quran and the Bible.
The teachings of the Quran about Satan and morality.
The content of the Quran and the scientific information.
These points are intended to help us in our “elimination process by deleting sources or authors that are out of the question.
Muhammad: We can start removing Muhammad from the list of possible authors of the Quran. It is simply impossible that he should have written the Quran; see points 1, 2, 3, 5 and 6 explained above.
Other Arab poets or scholars: we can also remove all other Arabs from the list; see points 2, 3 and 6.
Some non-Arabs: The reasons for deleting any Arab from the list apply equally to any non-Arab scholar, poet or religious figure.
Christian monks or Jewish rabbis (ie Judeo-Christian sources): This alternative source of the Quran is unreasonable in view of items 1, 2, 3, 4 and 6.
Satan (or other hidden spirits or extraterrestrials or anyone else on his side): These View is also inconceivable due to the points that were discussed in particular under 5.
Allah (ie God): In the absence of any alternative sources and authors for the Quran, one is more or less forced by reason to accept the Quran for what it claims to be: the revelation of God through His Prophet Muhammad, may God praise him. This attitude not only seems reasonable because it is the only way that cannot be eliminated objectively, but it is reasonable to assume that a book with such qualities and content can only come from the creator and leader of the people. Of all conceivable sources of the Quran, it is only the last alternative – God – who also calls himself the author of the Scriptures in the Quran.
So the belief that God is the author of the Qur’an persists, and the challenge (or adulteration test, Q.4: 82) is open to anyone to claim the Qur’an to be the revelation of God refute. If we have done this test ourselves, then the Muslim’s finding that the Quran is God’s Word appears to us no longer just as the product of blind faith but as the product of a very reasonable and well-considered judgment, given all the evidence. And indeed: after we have evaluated the evidence, it would be rather blind belief to say otherwise!
Note: The proof of the divine authorship of the Quran is also proof of the existence of the divine itself. God must exist as long as no other reasonably authorable author of the Quran can be obtained!
 See Norman Daniel’s Islam and the West: the Making of an Image, UK: Edinburgh University Press, 1989, p.83, 94, etc.
 Cited in HM Njozi, The Sources of the Quran: A Critical Review of the Authorship Theories, Saudi Arabia: WAMY Publications, 1991, p.96
 Maurice Bucaille, The Bible, the Quran and Science, Indianapolis: American Trust Publications, 1978
 Jeffrey Lang, Struggling to Surrender, Maryland : Amana Publications, 1994
 Malik Bennabi, The Quranic Phenomenon, transl. A.B. Kirkary, Indianapolis: American Trust Publications, 1983
 Keith Moore, The Developing Human, 3rd edition, Philadelphia: W.B. Saunders Co., 1982
 I.A. Ibrahim, Ein kurzer illustrierter Wegweiser, um den Islam zu verstehen, Houston: Darussalam Publishers, 1997
 H.M. Njozi, The Sources of the Quran: A Critical Review of the Authorship Theories, Saudi Arabia: WAMY Publications, 1991
 Gary Miller, The Basis of Muslim Beliefs, Kuala Lampur: Prime Minister’s Department – Islamic Affairs Division, 1995
 Maurice Bucaille, Die Bibel, der Quran und die Wissenschaft, Indianapolis: American Trust Publications, 1978
  ibid., S.163.