Islam is the youngest and fastest-growing major world religion. It was founded by Arabian visionary Muhammad (570-632 AD), who was born in the city of Mecca in Arabia. Muhammad claimed he received supernatural revelations from God through the angel Gabriel. These revelations were written down by others and compiled into a book called the Koran (or Qur’an). Islam today is comprised of two main schools: the majority Sunni school and the minority Shi’ite school. In addition, there are millions of Muslim mystics called Sufis. Islam is the second largest religion in the world (behind Christianity) with about 1.5 billion followers. Interestingly, the four nations with the largest number of Muslims today are all outside the Middle East – Indonesia, Pakistan, Bangladesh, and India.