Christianity and Islam are the two largest religions in the world and share a historical and traditional connection, with some major theological differences. The two faiths share a common place of origin in the Middle East, and consider themselves to be monotheistic.
The effect of the spread of Islam was an increase in trade. Unlike early Christianity, Muslims were not reluctant to engage in trade and profit; Muhammad himself was a merchant. As new areas were drawn into the orbit of Islamic civilisation, the new religion provided merchants with a safe context for trade. The application of sharia—Islamic law derived from the Koran—ensured a certain measure of uniformity in the application of criminal justice. Sharia law protected commerce and imposed stiff punishments for theft and dishonesty. Muslim jurists called qadis were established to resolve disputes through the application of sharia. Merchants were thus provided with a forum for making complaints and having them resolved in a consistent and systematic way. Trade and travel were not as risky or perilous as before and both thrived with the coming of Islam.
The correct answer to this open question is the following.
We are talking about two of the most important religions on planet Earth. Islam and Christianity have impacted the world in many positive ways. The number of people that follow the religious principles of Islam and Christianity indicates that these people are convinced of their respective precepts. Islam is based in the so-called "five Pillars of Islam," that includes fastening during the Ramadan days, a pilgrimage to Mecca at least one time in the life of a Muslim, and to share part of your wealth with the poor. On the other hand, Christianity is based on the teachings of Jesus of Nazareth that can be read in the Bible, specifically in the New Testament. Master Jesus taught that there is only one God, that he was the son of god as we are too. And everything he did, we have the possibility to do it. He taught that love is the base of everything.
The Abbasids overthrew the Umayyad dynasty in 750 CE, supporting the mawali, or non-Arab Muslims, by moving the capital to Baghdad in 762 CE. The Persian bureaucracy slowly replaced the old Arab aristocracy as the Abbasids established the new positions of vizier and emir to delegate their central authority.
