The Facts on Islam (Harvest House, rev. 1998), p. 6-7
What is Islam?
Islam is the world religion founded by an Arabian visionary named Muhammad (ca. 570-632 A.D.; var. sp.: Muhammed, Mohammed) 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, the Muslim Bible (var. sp.: Quran).
Islam today is comprised of two principal schools—the majority Sunni school (90%) and the minority Shi’ite school (10%). In addition, there are millions of Muslim mystics called Sufis. In America, Muslim influence is seen in traditional Islam as well as the militant, racist black Muslim movement.* There are now between 5 and 8 million Muslims in America and their numbers will apparently continue to expand for the foreseeable future.
*For documentation, see The Facts on Islam.