After giving those principles, here is just a proof by Bediuzzaman Said Nursi.It's a good response to those who say Islam is wrong and Quran is the word of Muhammed SAW:
" It is in no way possible for a human being to be successful in doing such a thing on his own, in fact, it is completely impossible. Individuals who resemble one another may imitate one another, those of the same kind may take on one another’s forms, those who are close to one another in rank or status may imitate one another and temporarily deceive people, but they cannot do so for ever. For in any event, the falseness and artificiality in their behaviour will show up their imposture to the observant, and their deception will not last. If the one who is attempting to imitate another under false pretences is quite unlike them, for example, if an uneducated man wants to imitate in learning a genius like Ibn-i Sina, or a shepherd assume the position of a king, of course, they will not deceive anyone at all, they will only make fools of themselves. Everything they do will proclaim, ‘This is an impostor.’
“Thus, to suppose -God forbid!, a hundred thousand times- the Qur’an to be man’s word is utterly impossible, no rational being can accept it as possible, to do so is a delirium like imagining to be possible something that is self-evidently impossible like a fire-fly being seen by astronomers as a real star for a thousand years; or a fly appearing to observers in the true form of a peacock for a year; or a bogus common private posing as a famous lofty field marshal, taking over his position and remaining in it for a long period without giving away his deception; or like a slandering, unbelieving liar affecting the manner and position of the most truthful, trustworthy, upright believer throughout his life and being completely unruffled before even the most observant while concealing his fraud from them.
“In just the same way, if the Qur’an is supposed to be man’s word, then it has to be supposed, God forbid, that that Perspicuous Book, which is considered to be clearly a most brilliant star, rather, a sun of perfections perpetually scattering the lights of truth in the heavens of the world of Islam, is like a fire-fly, a spurious sham made up by a counterfeiting human. And those who are closest to it and study it most carefully do not realize this, and consider it to be a perpetual, exalted star and source of truth. Together with this being impossible a hundred times over, even if you went a hundred times further in your diabolical machinations, O Satan, you could not make such an assertion, you could not deceive anyone of sound reason! Only sometimes you trick people by making them look from a great distance, thus making the star appear as small as a fire-fly.
“Thirdly: Also, if the Qur’an is imagined to be man’s word, it necessitates that the hidden reality of a criterion of truth and falsehood, which is miraculous in its exposition, and through the testimony of its fruits, results, and effects, is gilded with the most spiritual and life-giving, the most truthful and happiness-bringing, the most comprehensive and exalted qualities in the world of mankind, is, God forbid, the fabrication of a single unaided and unlearned man’s mind; and that the great geniuses and brilliant scholars who observed that being closely and studied him meticulously at no time saw any trace of counterfeit or pretence in him and always found him serious, genuine, and sincere.
“This is completely impossible, an idea so nonsensical as to shame the Devil himself, like dreaming up an utterly impossible situation. For it entails supposing one who throughout his life demonstrated and taught trust, belief, confidence, sincerity, seriousness, and integrity through all his conduct, words, and actions, and raised eminently truthful and sincere followers, and was accepted to possess the highest and most brilliant and elevated virtues to be the most untrustworthy, insincere, and unbelieving. Because in this question there is no point between the two.
“If, to suppose the impossible, the Qur’an was not the Word of God, it would fall as though from the Divine Throne to the ground, it would not remain somewhere between. While being the meeting-point of truths, it would become the source of superstition and myth. And if, God forbid, the one who proclaimed that wonderful decree was not God’s Messenger, it would necessitate his descending from the highest of the high to the lowest of the low, and from the degree of being the source of accomplishments and perfections to the level of being a mine of trickery and intrigue; he could not remain between the two. For one who lies and fabricates in God’s name falls to the very lowest of degrees.
“However impossible it is to permanently see a fly as a peacock, and to all the time see the peacocks’s attributes in the fly, this matter is that impossible. Only someone lacking all intelligence could imagine it to be possible.
“Fourthly: Also, if the Qur’an is imagined to be man’s word, it necessitates fancying that the Qur’an, which is a sacred commander of the community of Muhammad, mankind’s largest and most powerful army, is -God forbid- a powerless, valueless, baseless forgery. Whereas, self-evidently, through its powerful laws, sound principles, and penetrating commands, it has equipped that huge army both materially, and morally and spiritually, has given it an order and regularity and imposed a discipline on it that are such as to conquer both this world and the next, and has instructed the minds, trained the hearts, conquered the spirits, purified the consciences, and employed and utilized the limbs and members of individuals according to the degree of each. To imagine it to be a counterfeit necessitates accepting a hundredfold impossibility.
“This impossibility entails the further complete impossibility of supposing that one who, through his deliberate conduct throughout his life taught mankind Almighty God’s laws, and through his honest behaviour instructed man in the principles of truth, and through his sincere and reasonable words showed and established the straight way of moderation and happiness, and as all his life testifies, felt great fear of Divine punishment and knew God better than anyone else and made Him known, and in splendid fashion has for one thousand three hundred and fifty years commanded a fifth of mankind and half the globe, and through his qualities of renown is in truth the means of pride of mankind, indeed, of the universe, God forbid a hundred thousand times, neither feared God, nor knew Him, nor held back from lying, nor had any self-respect. Because in this matter there is no point between the two. For if, to suppose the impossible, the Qur’an is not the Word of God, if it falls from the Divine Throne to the ground, it cannot remain somewhere in between the two. Indeed, it then has to be accepted as the property of the very worst of liars. And as for this, O Satan, even if you were a hundred times more satanic, you could not deceive any mind that was not unsound, nor persuade any heart that was not corrupted.”
From:
http://www.lightofquran.info/15word.htm