[Below is a revised version of what I say in my History 121 class about Islam.  Class discussion is likely to move in a different direction, but the historical narrative below and the readings in Prothero, Smith, and Novak should help in the understanding of Islam as a World Religion.]
THE ROAD TO WHO KNOWS WHERE
ISLAM AND ITS IMPACT ON THE WORLD

I.  Introduction

Christianity is in general the most successful of the "world" religions, a religion able to function well as a state-supported, state-supporting faith, but a religion that arose (and thrived) amid state opposition, and a religion that can (if need be) survive, not only without the help of secular authorities, but in the face of vehement opposition from those authorities.

Christianity was a great source of strength both to the Byzantine empire and the Christian kingdoms that emerged in the West after the collapse of Roman power.  One by one, the Barbarian groups that had threatened Rome and even annexed much of its territory converted to Christianity.  Once converted, that had an interest in preserving much of Christian Rome, and many of them inherited the dream of renewing a society like that of Rome under Constantine.  Charlemagne, and the Holy Roman emperors, for instance, sought to create such societies.

Christianity might have grown and spread even more successfully had Christians not been faced with a great rival religion, Islam.  Islam is the 2nd most successful of the great world religions, and there is at least a chance that it might supplant Christianity as the world's number one faith. The likelihood is that Europe will end up majority Islamic in your lifetime.

So where does this religion come from?  Was it created?  Discovered?  Revealed?  And why is it so successful as a "world" religion?  The place to start is with a look at Muhammad himself.

II.  Life of Muhammad

Muhammad was born in AD 570 in Mecca in what is today Saudi Arabia.  Mecca was hardly the kind of community that one would expect would produce a world-changing individual.  It was relatively important in the local economy as a center for the caravan trade and as a site of religious pilgrimage, but it was not a major player in international affairs, not a place like Rome or Babylon or Athens, the kind of places that most typically produce world leaders.  Muhammad was orphaned at an early age, and his family wasn't among the elite types that usually produce world leaders.

At age 25, Muhammad married a woman named Khadijah.  Khadijah was 15 years older than Muhammad, but she was a wealthy woman, and this marriage had several advantages for Muhammad.  It enabled him to join at least the local elite--but, still, he was by no means even close to being among the "world changers."

But at age 40 something changed Muhammad's life--and, eventually, the course of the world.  Muhammad began hearing voices--and, at first, he was troubled, even borderline suicidal.  But the voice assured him that he wasn't going crazy or hearing a demon.  No.  Quite the reverse.  This was the angel Gabriel speaking.  Muhammad had been chosen by Allah to be his messenger!

Muhammad told Khadijah about the experience--and she believed him, becoming the first convert to Islam, but not the last.  Muhammad preached his message in Mecca and brought in some additional converts. 

But Muhammad was creating trouble in Mecca for people in the religion business.  By teaching that there was only one god, Muhammad was undercutting those who made money from those involved in the polytheistic worship ceremonies that had, up to this point, been the main focus of Meccan religious life.  Things got  so tense in Mecca, that, in AD 622 (Year 1 by the Moslem calender), Muhammad's followers left Mecca for a town to the north, a town at the time called Yathrib but later called "Madinat al Nevi," the city of the prophet.  We shorten that to Medina.

In Medina, Muhammad and his followers found wider acceptance and they were even able to take control.  From their base at Medina, they began attacking Meccan caravans, and the Meccans responded by sending out forces against Muhammad.  After a number of skirmishes, the forces of Muhammad were eventually triumphant, and, in AD 630, Muhammad and his men were able to take over Mecca as well.  Two years later (AD 632), Muhammad dies.

Small potatoes seemingly.  A footnote to history.  None of the battles fought involved more than a few thousand soldiers or more than a couple of hundred casualties.  Control of Mecca and Medina wasn't a particularly logical start to controlling a large part of the world.  But shortly after Muhammad's death, his Arab followers began an expansion nearly unprecedented in history.  Within eighty years, the Moslems controlled an empire that extended west across north Africa all the way to Spain, dominated Palestine, Syria, and Asia Minor, and continued east almost to the Indus.

How could this have happened?  Well, Muhammad had created a religion that united and inspired the Arab people.

What were the strenghths of this religion, and how did it transform the Arabs?

III.  The Qur'an and the Five Pillars of Islam

One strength of the religion is the Koran (Qur'an), the holy book of Islam.  The Koran is about the same length as the New Testament.  It's language is apparently beautiful and poetic, making it easy to memorize.  But more important than the beauty of the language: the teaching of the Koran.

Moslems themselves often summarize the Koran's teaching in accord with what are called the Five Pillars of Islam.

[See this online summary of the Five Pillars of Islam]

The Five Pillars include the following:

1.  Faith.  To be a Moslem was believe certain things.  The basic faith is summarized in what is called the shahada (there is no God but Allah, and Muhammad is his prophet).  The simple statement of faith is certainly a strength of Isalm.   Note that the is none of the complexity  that goes with the Christian creeds.  Say: He is Allah, the One! Allah, the eternally Besought of all! He begetteth not nor was begotten. And there is none comparable unto Him. (Surah 62:1-4).

2.  Prayer.  A Moslem is expected 5 times a day to join public prayer toward the city of Meccas.  This is a powerful way of using social pressure to strengthen religions belief.

3.  Fasting.  A Moslem is expected to fast from sun-up to sundown during the month of Ramadan.  Fasting is a powerful tool in making people focus on their religion faith and to help them feel they are drawing closer to God.

4.  Alms.  A Moslem is expected to give a percentage of their income to the poor.  This is an important way of helping alleviate class tension in the Islamic world.

5.  Pilgrimage.  A Moslem is expected to make a special pilgrimage to Mecca.  This pilgimage, the Haj, is often a life-transforming even for Moslems.  In addition, it brings together Moslems from all over the world and tends to be a force to unite them.  Whatever else might separate Moslems, they worship together with other Moslems when they make their Haj.

6.  Holy War.  Yes, that's more than five pillars, but holy war, Jihad, is so important to the growth of Islam that it is almost a sixth pillar of the religion.  Moslem men are promised that, if they die fighting for their faith, they go straight to paradise where all sorts of delights await.  George Bush talked of Islam as a religion of peace.  This really isn't true.  Islam is a fighting man's religion par excellence, and fighting peoples again and again have found it an especially appropriate religion. Sura VIII of the Koran is an entire chapter/book dedicated to instruction on how to deal with the spoils of war.  And while Moslem soldiers are told they are not to fight primarily for booty, they are certainly entitled to enjoy what they acquire in the process of extending dominion of Allah. Here's some of what Muhammad had to say to fighting men:

"Fight in the path of God with those who fight with you;--but exceed not; verily God loveth not those who exceed.--And kill them wheresoever ye find them, and thrust them out from whence they thrust you out; for dissent is worse than slaughter; but fight them not at the Sacred Mosque, unless they fight you there, but if they fight you, then kill them: such is the reward of the infidels! But if they desist, then verily God is forgiving and merciful.--But fight them till there be no dissent, and the worship be only to God;--but, if they desist, then let there be no hostility save against transgressors."

Shortly after the death of Muhammad, Holy War began in earnest.  Moslems pushed int o Syria and Iraq (633), Egypt (639), Persia (640) and eventually Spain (711).  How were the Moslems able to expand so rapidly?

IV.  Reasons for Moslem Success

1.  The Moslems were lucky enough to have a series of capable men at the top, "caliphs."  Caliph is sort for a longer phrase that means "successor of the prophet of God."    The Caliphs were both the secular and spirtitual leaders of Islam, and, in this case, the "one strong man at the top" thing worked pretty well--as long as the Moslems agreed on who that man should be.  Not surprisingly, agreement wasn't always easy, and, relatively early, the Moslems split over who the rightful Caliph was.  This is where the Sunni/Shiite division starts, with the Shiites believing that only the successors of Ali should have been recognized as Caliphs.

2.  The Moslems were able to expand in large part because the two great powers of the eastern mediterranean had exhausted one another in years of fighting.  The Persians and Byzantines fought each other for years, and these struggles left both so weakened that they had a hard time fending of the Moslems.

3.  Christian resistance was half-hearted.  Iconoclasts and Monophysites preferred the rule of Moslems (who would at least tolerate them) to the rule of "orthodox" Christians that they regarded as heretics. Iconoclasts in particular prefered the "no images allowed" policy of the Moslems to the "idol worshipping" orthodox.   Futher, Christians were allowed by the Moslem rulers to keep their faith: no need to fight and die when one could remain a Christian if one wanted.   Eventually, however, many of the Christians converted to Islam because of social/economic pressure.  A Christian paid more in taxes than a Moslem, and many Christians eventually changed their faith just to lower their taxes.

4.  The Moslems had a great knack for adapting what they could from other cultures.  The Persian bureaucratic set up, for instance, was well designed for governing a large, diverse empire, and the Moslems found it useful to adopt that set up for their own purposes.

5.  Islam had the ability to absorb/assimilate new converts easily.  Even some of the early Caliphs had initially opposed Muhammad.  An enemy, once converted, became your friend and ally.

6.  Islam is exactly what *men* want in a religion.  It's a challenging religion, but not too much of a challenge.  It sets the bar exactly where we want it: not too high, not too low.  Examples:

a.  Revenge.  Where as Christians are told they must turn the other cheek, Moslems are permitted revenge if they want to take it, although showing mercy is to their credit:

And We prescribed for them therein: The life for the life, and the eye for the eye, and the nose for the nose, and the ear for the ear, and the tooth for the tooth, and for wounds retaliation. But whoso forgoeth it (in the way of charity) it shall be expiation for him. Whoso judgeth not by that which Allah hath revealed: such are wrong-doers. (Surah 5:45).

b.  Treatment of women.  Whereas Christian men are told to love their wives as Christ loved the church, Islam puts men clearly in charge:

Men are in charge of women, because Allah hath made the one of them to excell the other, and because they spend of their property (for the support of women). So good women are the obedient, guarding in secret that which Allah hath guarded. As for those from whom ye fear rebellion, admonish them and banish them to beds apart, and scourge them. Then if they obey you, seek not a way against them. Lo! Allah is ever High Exalted, Great. And if you fear a breach between them twain (the man and wife), appoint an arbiter from his folk and an arbiter from her folk. If they desire amendment Allah will make them of one mind. Lo! Allah is ever Knower, Aware. (Surah 4:34-35).

c.  Divorce.  Where as Judaism allows divorce but looks on it as a great negative and Christianity forbids divorce altogether (or, at least, allows it only very rarely).  Islam  allows a man to divorce his wife for any reason just by saying three times "I divorce you."

[More examples in class.  I compare/contrast how Islam and Christianity deal with giving, lust,  etc.]