The basis for Islamic doctrine is found in the Qur’an (Koran). Muslims believe the Qur’an is the word of God, spoken by the angel Gabriel to Muhammad. The Qur’an was only in oral form while Muhammad was living, which means it was constantly interpreted by Muhammad and his disciples. It was written down in the caliphate of Abu Bakr. It alone is infallible and without error. The Qur’an is comprised of 114 surahs, or chapters, arranged from longest to shortest. For Muslims Muhammad was the last and most perfect of God’s seven prophets or messengers to mankind.

In addition to the Qur’an, other documents are also referred to by followers of Islam. A number of additional sayings of Muhammad were complied in the Hadith (“tradition”). The Torat (of Moses), Suhuf (books of the prophets), Zabur (psalms of David), and the Injil (gospel of Jesus) are also studied and considered to be revelations, although they are believed to have been corrupted through time.