Quran-
The Noble Quran is the Muslim holy book. It is not, as is commonly thought, a biography of Muhammad, rather its a book of guidance for mankind straight from their God - (Allah).
The book talks about 100s of different topics, but the whole book revolves around one idea: The singular, simple and pure concept of one God ("say he, Allah is one" 112:1) (tawheed- in arabic). It teaches that the purpose of life is to accept God without any partners and then to worship God in the way he has taught us( see previous post).

The Quran was revealed in many different revelations in different times and circumstances to the messenger of God- Muhammad (pbuh). Muhammad was illiterate so it was very surprising for the arabs at the time, for Muhammad to be reciting what they admitted was so beautiful that it was "not the speech of man". The Quran is always without fail God speaking to humanity, rather than Muhammad speaking from his own thoughts. It was completed in 23 years. This revealed Quran was taught to the companions of Muhammad and they learnt it by heart (its very possible -I know many many people who have done this 100,000s in the world, probably in the millions). It was also written down, dictated by Muhammad to his scribes.

After the messenger of God passed away, the Quran was compiled into one book by the Khalifa (ruler) of the muslims, so as to safeguard the Quran from any corruption. This was done quickly as many Huffaz ( memorisers of the Quran) were dying in battles so the Quran had to be written down. The companions all threw themselves into contributing to this compilation. Now the person doing the compilation was himself a Haffiz ( memoriser of the entire Quran). But he didnt rely on his memory and his copies....he said that for every verse in the Quran to be safely included, there had to be a written record of it, written by someone who was dictated the verse directly from Muhammad and atleast 2 people who knew the verse by heart. Thus the Quran was compiled.

Later on another compilation took place, so as to give the companions who were away fighting at the time of the first compilation, a chance to contribute to the honoured task of compiling the Quran. - This compilation exactly matched the first one! so 2 seperate compilations using different sources got exactly the same verses!

This is a far cry from the Judaeo-Christian scriptures, penned by anonymous authors, each with their own ideology to spread, with many contradictions and even clear-cut borrowing form each other! They are essentially (inaccurate) biographies of various people, with little to nothing directly from God(God doesnt really address mankind in these texts). The Bible was compiled 150-300 years after Jesus. The Quran on the other hand was compiled using authentic sources, with all people involved known, along with their life stories and character, with multiple independent sources all corroborating and supporting each other. This was done within only 2-4 years after Muhammads death! (note: closer to time=less chance of information loss)