Religion shapes civilizations. Islam has had a profound positive shaping of the western world.
1. The Political Unification of the Arabian Peninsula (and beyond). During Mohammed’s time, the Arab people were in constant warfare with each other. Various tribes competed for territory and trade routes. Bandits and pirates were everywhere, and the economy really couldn’t grow much. Mohammed united these people under one banner (albeit after his death). From there, this civilization flourished and prospered while their neighbors languished.
2. The political climate of those times was very much “conquer or be conquered”. If a nation was weak economically, it eventually became weak militarily. And a weak military eventually meant being conquered by someone stronger. So smaller nations eventually became part of bigger nations — without the approval of the smaller nations. Whatever conquesting the Muslims were doing really was no different than what the non-Muslim world was doing — or wanted to do.
3. This flourishing civilization created the field of mechanical engineering. The Muslims devised and analyzed all sorts of wind-powered and animal-powered contraptions that moved water to irrigate fields and grind grains. These inventions enabled Musilm population to grow. This engineering eventually led to other technological achievements that were later borrowed by the Europeans.
4. The Muslims invented the concept of the university, where its wisest men could teach young people their wisdom. Elite families of Europe were sending their sons to Toledo, Alexandria, and other university towns to get their education for engineering and medicine. It was the Muslims who indirectly led the Christians out of the Dark Ages.
5. Although Muslims did not invent the rule of law, they were great practitioners of law. Underneath the ruling Muslim elites playing their games of power accumulation, the law served the common people fairly and honestly. This contributed to the betterment of that society.
6. Around 1000 AD, the Muslim cites of Alexandria, Bagdad, and Tripoli had underground sewers, law and order, night lighting, and other features of an advanced civilization for that time. In contrast, London, Berlin, and Paris were a fraction of the size, with households throwing their waste on the streets and bandits were preying on unarmed escorts outside the cities.
7. Muslim cities allowed Jewish and Christian communities to grow and flourish under their rule. The Koran has instructed Muslims to be kind to the “people of the Book,” and from a historical perspective, this law was followed reasonably well. However there was no provision for Zoroastrian, Buddhist, and Hindi followers; so these groups did indeed suffer from Muslim imperialism.
8. While there were some big battles between Christians and Muslims in the Crusader times, the Muslims, for the most part, allowed the Christians to stay in the Levant. Not only were they adhering to the “be kind to the people of the book” law, it was good for business in that region. Christian pilgrims brought a lot of wealth to the Muslims — which indirectly kept Europeans impoverished, relatively speaking.
9. Sunni Islam eventually split into five main sects (Hanafi, Maliki, Shafi, Hanbali, and Zahiri. Although these groups came to different theological conclusions of the Koran, they, historically speaking, got along reasonably well. If there was any society that first practiced the concept of “freedom of religion,” it was the Sunni Muslims.
I can already hear the Christian apologists denouncing whatever I have said here. They will be quite eager to depict the harder of edges of the Muslim world at that time (and there were hard edges). The Muslims under the ISIS banner are an aberration of history; incapable of creating any advanced civilization that the followers of Islam did 1000 years ago. We cannot judge an entire religion on this small group.