These days it’s urgent for Christians to read and understand the Koran in order to get a better handle on a religion that is so much in the headlines. But that asks a lot, because the Koran is a hodgepodge of early and later chapters, arranged in order of length from longer to shorter chapters, thus intermingling the early thoughts of Muhammad from Mecca with the very different sayings after the flight to Medina.
In A Simple Koran , Bill Warner helps to overcome the confusion by rearranging the Koran into chronological order over the twenty-three years in which Muhammad propagated his new religion. This approach, consisting almost entirely of texts from the Koran, with occasional subtitles or explanations, offers a good introduction to how Islam evolved during Muhammad’s life, as well as insights into the crucial division between what Aayan Hirsi Ali has called  “Mecca Muslims” and “Medina Muslims.”
The early sections of the Koran, from Mecca, stem from Muhammad’s conversion to monotheism from the multiple polytheistic religions prevailing around the Meccan shrine of the Kaaba. Some sources say that there were as many as 360 deities worshiped in Mecca. Muhammad preached subjection to the one and only God, Allah.
But there was a slip-up: Muhammad seemed to allow three goddesses to share veneration with Allah. According to ‘Ali Dashti’s biography, Twenty-Three Years  two verses in Sura 2:19-22 originally said, Have you thought about Lāt and ‘Ozzā? And Manāt, the third one, the other one? Those are the cranes aloft. So their intercession may be hoped for.
This passage seemed to recognize the divinity of the three goddesses, along with Allah. But Allah eventually reprimanded Muhammad for these “Satanic Verses,” which in later versions of the Koran were corrected. Strict monotheism was preached thereafter. (Salman Rushdie wrote a novel involving this passage and is still under the Ayatollah Khomeini’s fatwa calling for his death.)
The early parts of the Koran re-write the Old Testament, telling stories about how Abraham, Lot, Moses, etc. were all actually Muslims, and how those who rejected Islam ended up in hell. Numerous imaginative stories about Moses appear – usually having little to do with the Biblical version.
Such Islamic revisions of Old Testament histories were accompanied with constant warnings of eternal torture in hell for Kafirs (non-Muslims) who do not convert. This begins a constant theme throughout the Koran, which contains 290 verses about Hell, and over 300 references to the fear of Allah, to whom slavish Islam (“submission”), as to a Master, is required. For example, The Kafirs among the People of the Book and the idolaters will burn for eternity in the Fire of Hell. Of all the created beings, they are the most despicable. (98:6)
In contrast, those who accepted Muhammad’s message were promised a heavenly reward in which they would be “on decorated couches,” waited on by “immortal young boys” bringing fruits and wine and the “flesh of birds,” as well as the amorous attentions of virginal houris.
The people of Mecca, doubting Muhammad’s prophetic credentials, asked him for signs that he was an authentic prophet. Muhammad cited a litany of things as signs – “the succession of night and day,” “the rain which Allah sends,” “lightning,” “the changing of the winds,” “green foliage and grain,” “your slumber during the night and day,” “your quest for Allah’s bounties,” “the ships in the sea like mountains,” etc. Exasperated by the persistent requests for clear signs, Muhammad responds, The signs are in the power of Allah alone. I am only a plain warner. Is it not enough for them that We have revealed to you the Book to be recited to them? (29:48) In other words, the Koran itself is a sufficient miracle confirming him as a prophet.
Muhammed didn’t have much success in Mecca; he ended up with only 150 converts. But he had some followers in Medina, and he fled there when the situation became dangerous in Mecca.
The Hegira (emigration) of Muhammad and his disciples to Medina took place in 622. Medina was half Jewish and half Arabian. The Jews, the wealthy class, were largely farmers and craftsmen. They had allies among the Arabs, but an atmosphere of animosity and jealousy prevailed. Some Arabs believed that a prophet would come and lead them to victory over the Jews. Muhammad very soon seemed the one. They took an oath of loyalty to Muhammad, and offered to protect him with arms, if necessary.
Muhammad eventually began to function as a warlord, and started sending fighters on armed raids against trade caravans coming to Mecca. Over nine years, he carried out sixty-five raids (in twenty-seven he was personally present), as well as various assassinations, and executions.
The threats of hell for rejecting Muhammad now became graphic – Allah will “destroy your faces and twist your heads around backwards” (4:47), give unbelievers “clothing of fire,” “pour boiling water on their heads,” “scald their insides and their skin,” and beat them with “iron rods” (22:19).
For Muhammad himself, Allah began to grant special privileges: The spoils of war (limited to one-fifth of the totals), and wives and slave-girls beyond the limits applied to others (Muhammad’s amorous retinue eventually included nine wives and several slave-girls).
A new wave of violence began when the Jews of Medina and even many Arabs rejected Muhammad’s claim to be a prophet sent by Allah. Islamic jihad became essential to spreading Islam in Arabia and elsewhere. A quarter of the verses at Medina are exhortations to jihad, and promises about the rewards not only for the Muslim community but for individual warriors.
In his final years, Muhammad began acting like a prophet/king. Every aspect of life came under his control – times of prayer, food and drink prohibitions, the wearing of veils, inheritance, wills, punishments for crimes, distribution of taxes, etc. – all specified as Allah’s mandates.
In sum, a chronological/biographical reading of the Koran brings out the tremendous differences between the earlier and later parts. There is no jihad in the Meccan Koran, no anti-Semitism, only peaceful calls for conversion. But in Medina, we have the gradual formation of a veritable army, inspired to literally conquer the world for Islam.
The “religion of peace,” therefore, does have some Koranic foundation, but as Islamic history and contemporary events make clear, there is perhaps even greater Koranic justification for violent jihad.