Before we turn to a consideration of Islam's current worldwide expansion, we need at least to mention that there are a multitude of different Islamic sects. The two largest groups are the Sunnites and the Shi'ites, of whom the Sunnites make up about 90 percent of all Muslims. Most Muslim countries, such as Egypt, Saudi Arabia and Pakistan, are largely Sunnite. They derive their name from Sunnah, which "refers to the deeds and words of the prophet."44 Hence, they are the traditionalists of Islam, following the traditions of Muhammad (which were passed on orally for 200 years before they were committed to writing) as authoritative only behind the Qur'an itself.
The Shia or "sect of 'Ali" broke off from the main body of Muslims in the first century A.H. The division arose over a dispute concerning the succession of leadership after Muhammad's death. The Shi'ites, who favored Muhammad's son-in-law and nephew Ali, believed that the caliph should have been divinely appointed, not elected by mere men."45
Besides the bitter controversy over the caliphate a second major difference between the Sunnites and Shi'ites concerns the doctrine of the imam. For the Shi'ites imams are "divinely appointed and divinely guided" leaders, and new ones appear from time to time when most needed. Several times in Shi'ite history men have claimed this position. The Sunnites believe the imam to be merely the leader of the Friday prayer service.46
Today the Shi'ites are most populous in Iran, Iraq, Lebanon and parts of Africa. The consequence attached to the office of ayatollah shows the tendency Shi'ites have of putting "confidence in a charismatic figure rather than in a book."47