The Myth:
Muhammad was a peaceful man who taught his followers to be the same. Muslims lived peacefully for centuries, fighting only in self-defense - and when it was necessary. True Muslims would never act aggressively.
The Truth:
Muhammad organized 65 military campaigns in the last ten years of his life and personally led 27 of them. The more power that he attained, the smaller the excuse needed to go to battle, until finally he began attacking tribes merely because they were not part of his growing empire.
After Muhammad’s death, his successor immediately went to war with former allied tribes which wanted to go their own way. Abu Bakr called them 'apostates' and slaughtered anyone who did not want to remain Muslim. Eventually, he was successful in holding the empire together with blood and violence.
The prophet of Islam's most faithful followers and even his own family turned on each other as well. There were four caliphs (leaders) in the first twenty-five years, each of which was a trusted companion of his. Three of these four were murdered. The third caliph was murdered by those allied with the son of the first. The fourth Caliph was murdered in the midst of a conflict with the fifth, who began a 100-year dynasty of excess and debauchery that was ended in a gruesome, widespread bloodbath by descendents of Muhammad’s uncle.
Muhammad’s own daughter, Fatima, and his son-in-law, Ali, who both survived the pagan hardship during the Meccan years safe and sound, did not survive Islam after the death of Muhammad. Fatima died of stress from persecution within three months, and Ali was later assassinated by Muslim rivals. Their son (Muhammad’s grandson) was killed in battle with the faction that became today’s Sunnis. His people became Shias. The relatives and personal friends of Muhammad were mixed into both warring groups, which then fractured further into hostile sub-divisions as Islam expanded.
Muslim apologists, who like to say that is impossible for today's terrorists to be Muslim when they kill fellow Muslims, would have a very tough time explaining the war between Fatima's followers and Aisha to a knowledgeable audience. Muhammad's favorite daughter and his favorite wife were both explicitly held up by him as model Muslim women, yet they were both invoked by other companions as they engaged in violent civil war following his death. Which one was the prophet of God so horribly wrong about?
Muhammad left his men with instructions to take the battle against Christians, Persians, Jews and polytheists (which came to include millions of unfortunate Hindus). For the next four centuries, Muslim armies steamrolled over unsuspecting neighbors, plundering them of loot and slaves, and forcing the survivors to either convert or pay tribute at the point of a sword.
Companions of Muhammad lived to see Islam declare war on every major religion in the world in just the first few decades following his death - pressing the Jihad against Hindus, Christians, Jews, Zoroastrians, and Buddhists.
By the time of the Crusades (when the Europeans began fighting back), Muslims had conquered two-thirds of the Christian world by sword, from Syria to Spain, and across North Africa.
Millions of Christians were enslaved by Muslims, and tens of millions of Africans. The Arab slave-trading routes would stay open for 1300 years, until pressure from Christian-based countries forced Islamic nations to declare the practice illegal (in theory). To this day, the Muslim world has never apologized for the victims of Jihad and slavery.
There is not another religion in the world that consistently produces terrorism in the name of religion as does Islam. The most dangerous Muslims are nearly always those who interpret the Qur’an most transparently. They are the fundamentalists or purists of the faith, and believe in Muhammad’s mandate to spread Islamic rule by the sword, putting to death those who will not submit.
The holy texts of Islam are saturated with verses of violence and hatred toward those outside the faith. In sharp contrast to the Bible, which generally moves from relatively violent episodes to far more peaceful mandates, the Qur’an travels the exact opposite path (violence is first forbidden, then permitted, then mandatory). The handful of earlier verses that speak of tolerance are overwhelmed by an avalanche of later ones that carry a much different message. While Old Testament verses of blood and guts are generally bound by historical context within the text itself, Qur'anic imperatives to violence usually appear open-ended and subject to personal interpretation.
From the history of the faith to its most sacred writings, those who want to believe in "peaceful Islam" have a lot more of Islam to ignore than do the terrorists. By any objective measure, the "Religion of Peace" has been the harshest, bloodiest religion the world has ever known.