MECCA, Saudi Arabia (Christian Examiner) – Islam is dated to the early part of the 7th century, but its roots go even deeper and include influences from Christianity and Judaism.
Muhammad's conversion from polytheism to monotheism, the belief in one God, resulted from his interaction with both Jews and Christians. However, he came into conflict with both—rejecting the many symbols of Christians, including the crucifix, as idolatry, and facing opposition from Jews in Jerusalem as well as in Medina in Arabia.
Despite these diffferences, the Qu'ran, which Muslims claim was given by God through the angel Gabriel to Muhammad, affirms as sacred the Hebrew Torah, the Psalms of David and the Gospels of Christ calling them "the previous scriptures" (Sura 4:163 and 5:44-48).
So, when he unveiled his new faith to the people of Mecca in 610, according to the Council on Foreign Affairs, Muhammad had incorporated some Jewish and Christian traditions and expanded upon these with a set of laws to govern "most aspects of life, including political authority." Thus, by spreading his religion, by the time of his death in 632, he had consolidated power in Arabia and within a century, his followers built an empire stretching from Central Asia to Spain.
But CFR reports that a conflict over succession split the religion--with some within it arguing that only those from the bloodline of Muhammad were legitimate leaders and others contending that leadership should be awarded to qualified individuals regardless of their family lines. Ultimately, Shias (from "shi'atu Ali," or "partisans of Ali") backed Ali ibn Abi Talib, the cousin and son-in-law of Muhammad. The rival Sunnis chose to follow Abu Bakr a companion of Muhammad's. Sunni means "follower of the sunna" (or "way").
The Central Intelligence Agency's World Factbook states that both sects share belief in the Five Pillars of Islam, which include the pilgrimage to Mecca as a sacred obligation (that must be completed at least once), and the celebration of Ramadan (a month-long holiday of religious observances).
But the difference about succession split the religion deeply.
Ali became caliph in 656 and ruled only five years before he was assassinated, CFR details. The caliphate, or political and religious authority, passed from the Arabian Peninsula to the Umayyad dynasty in Damascus, Syria, and later to the Abbasids in Baghdad, now in modern day Iraq. Then Sunnis "killed Ali's son, Husayn, and many of his companions in Karbala." Karbala, also located in modern day Iraq, gave Shias a moral platform with the people, and Sunni caliphs worried that Shia imams—descendents of Husayn—would exploit the massacre to rally Muslims to topple Sunni monarchs.
Sunnis use the term imam for the men who lead prayers in mosques.
But for most Shias, an imam is one of twelve historic figures of Muhammad's bloodline, the last of which in 939 A.D. entered a state of occultation, or hiddenness, to return at the end of time. They vest religious authority in their senior clerical leaders called ayatollahs, CFR adds.
Today Sunnis make up about 85 percent of the world's Muslims, and the battles fought between the two factions helps to explain the demographic distribution of Islam's sects, says CFR. Shias hold a majority in "Iran, Iraq, Azerbaijan and Bahrain, and a plurality in Lebanon, while Sunnis make up the majority of more than forty countries from Morocco to Indonesia."