The Qur'an is the concrete tangible Word of God. It is The Muslims Holy book and the main source of every Muslim's faith and practice.The Qur'an identifies itself to us that God is its Author, as God tells us in Surah 55 verse 1 and 2:
"God the Merciful has taught the Qur'an".The Qur'an tackles all subjects that concern human beings like wisdom, doctrine, worship, transactions, law, etc., but its basic theme is the relationship between Allah and His creatures. At the same time it provides guidelines and detailed teachings for a just society, proper human conduct, and an equitable economic system, and it gave humanity directions that prevents them from lots of evils.
The Qur'an was revealed to Prophet Mohammad (PBUH) in Arabic language, as God Almighty says :
"Thus We have revealed it an Arabic Qur'an".So any Qur'anic translation, either in English or any other language, is not a different version of the Qur'an but translation of the words of the Qur'an, for Qur'an has one and only one version.
“Qur’an” is Allah’s speech, and not a created book, that may perish, nor is it an attribute of any created thing. Prophet Jibreel (Gabriel) brought down the Qur’an to Mohammad (PBUH), bit by bit as circumstances warranted, over a period of twenty-three years. The Prophet Mohammad (PBUH) started memorizing every verse he received from Jibreel, and recites them to his wife Khadeeja and his companions, who happened to be with him. Also he used to order them to write the verses down immediately, and that's how Qur'an was preserved and prevented from losing any of its verses.
Prophet Mohammad (PBUH) himself used to keep a copy of the verses of Qur'an he receives in his house. The Qur’an, the last of Allah’s Scriptures, is divided into 114 suwwar of different length. It is one of the fundamental sources of Islamic teachings. Allah revealed some of the Qur’an’s suwar and verses in Mekkah and the rest He revealed in Madinah.
The Mekkan suwwar and verses basically discusses the issues of aqeedah such as tawhid (Faith and Belief), the belief in the Oneness of Allah, the signs of the existence of Allah, the belief in all Prophets and Messengers He sent to humanity, the belief in His Angels, and the belief in the Day of Judgment. Prophet Mohammad (PBUH), stressed the Oneness of Allah, so did all the Prophets and Messengers of Allah before him, beginning with Adam and ending with Mohammad, peace be upon them all. On the other hand the suwwar that were revealed in Madinah dealt with different actions of the individuals and every aspect of life; putting humanity on the right track, it also explains forms of worship.
Authenticity of the Qur’anGod Almighty says:
"And if you have doubt about what We have revealed (Qur'an) to Our servant (Mohammad), then compose a chapter like it, and call upon your helpers other than God if your claims are true "
He also says: "We are the One Who has revealed the Qur'an, and We Will most surely preserve it"