It is believed that Prophet Muhammad had received revelations from Allah for 23 years. At first, these revelations were preached by the prophet verbally. Later Muhammad's teachings were set down in a book called the Quran (Koran). After Muhammad's death all the teachings of Muhammad were compiled under the direction of the first Sunni Caliph Abu Bakr. The work was completed about 1,400 years ago.
Composed in 114 verses or surah(s) of varying lengths, the Quran covers a wide range of subjects. It puts a special emphasis on the concept of oneness of god and his concern about the spiritual and worldly welfare of man. The holy scripture also enlightens on the creation of the world, specially, of man; of good and evil spirits; man's responsibility for his actions; the Day of Judgement; the final account; and rewards and punishments.
The book also contains rules and regulations regarding worship and the life of the community, the laws of the family: like marriage, divorce and inheritance. Since the Quran is said to be the very word of god, it is untranslatable. Nevertheless, for those who don't understand Arabic, the Quran has been explained and translated into almost all world languages. Still, every Muslim is expected to learn the Arabic script to be able to read the original text, even if he does not understand its meaning in Arabic.