Islam is a religion founded and based on faith in one supreme God, Allah.<br />Every follower of Islam believes in this central doctrine and in Prophet Muhammad being the last messenger of God. The Quran, the holy book of the religion is a compilation of all of God's revelations to the Prophet. God revealed his message to the Prophet Muhammad through the archangel Gabriel, about the onenness of God, how to worship him, and the perfected way of life. Therefore the Quran is considered the unchanged word of God and the constitution and the guide for Muslims in this life.