Since the death of Muhammad in A.D. 632, Muslims have been faced with the fate of all major world religions: division. For Islam, this began as Muslims tried to choose a leader after the untimely death of their prophet. With some believing their leader should be the most qualified man, and others advocating for Muhammad's closest male relative, the newly formed brotherhood was split. Over the centuries, this rift has inspired approximately 1.3 billion Muslims to call themselves Sunni, while about 257 million consider themselves Shi'ites.

Though many non-Muslims view Islam as a monolithic religion, Islamic beliefs are as diverse and divided as any other religious movement. (Remember the Sufis, for example?)

Today, after fourteen centuries of Islamic history, many orthodox and heterodox movements have appeared. While most of these groups continue to celebrate their Islamic roots, some conservative Muslims view them as apostates and infidels. Here are a few controversial factions.

Alawites (a.k.a. Nusayri)

Found primarily in the mountains that line the northwest Mediterranean coast, today about 2 million Arabs call themselves Alawites. Inspired by the teachings of the ninth-century Shi'ite theologian Muhammad bin Nusayr, Alawites have unique beliefs and practices, which some Muslims view as blasphemy.

An almost Trinitarian concept of Ali, Muhammad, and God being one in essence is the most striking Alawite belief. This sect is also criticized for not observing Islam's five pillars, for not meeting in mosques, and for celebrating traditionally Christian and Zoroastrian holidays.

The five pillars of Islam are:

• Faith or belief in the Oneness of God and the finality of the prophethood of Muhammad

• Establishment of the daily prayers (five times a day)

• Concern for and almsgiving to the needy

• Self-purification through fasting during the month of Ramadan

• The pilgrimage to Mecca for those who are able (the Hajj)

Despite opposition from some Muslim leaders, Alawites believe they are Shi'ite Muslims.

Like his father before him, Syria's president Bashar al-Assad is an Alawite. Though less than 10 percent of all Syrians are Alawites, this minority has ruled the nation since 1963.

Alevi-Bektashis

As a unique synthesis of Sufism, Shi'ism, and pre-Islamic religious beliefs, Alevi-Bektashism is a flexible and complex movement. Inspired by the teachings of a twelfth-century mystic named Haji Bektash Veli, nearly 15 million Turkish and Eastern European people have combined aspects of all the major world religions with a view that holds humanity and divinity as one and the same.

Like the Arab Alawites of south-central Turkey, eastern Syria, and northeastern Lebanon, Alevi-Bektashis do not observe Islam's five pillars, though Muhammad and the Qur'an are held in high regard. If you ask an Alevi-Bektashi if he is Muslim, he most likely will reply, “I am Muslim, Jewish, Christian, Buddhist, and atheist, but most importantly I am human.”

Druze (a.k.a. Mowahhidoon)

Though the exact origins of this movement are unclear, the Mowahhidoon (Arabic for “Monotheists”) emerged in the 800s, believing they were a new interpretation of Judaism, Christianity, and Islam. In their view, the other three had lost the true meaning of religion by focusing on rituals and laws. In contrast, the Mowahhidoon sought the “pure path,” which incorporated aspects of Greek philosophy and Hindu spirituality with traditional monotheism.

In the late 900s, a Mowahhidoon leader named Darazi announced that the Fatimid Caliph al-Hakim was the incarnation of God. Although many initially accepted this teaching, his followers eventually rejected Darazi. Because of Darazi's spectacular claims, outsiders used the name “Druze,” a variation of Darazi's name, when referring to the Mowahhidoon.

Because members of this sect have kept the details of their religion secret, many non-Mowahhidoon have speculated about their beliefs and practices. The Mowahhidoon are by definition strict monotheists. Unlike most monotheists, the Mowahhidoon believe that each soul is reincarnated from life to life and that heaven and hell are states of mind rather than destinations. As other offshoot groups have done, the Mowahhidoon have rejected the five pillars of Islam, causing many Muslims to reject them.

Today, there are about a million Mowahhidoon living around the world, with nearly 300,000 living in Lebanon, Syria, and northern Israel. The Mowahhidoon are ethnically Arabs, yet because they do not accept converts or marry outside of the faith, they have developed a distinct, almost ethnic identity.