From the oasis cities of Makkah and Madinah in the Arabian desert, the message of Islam went forth with electrifying speed. Within half a century of the Prophet's death, Islam had spread to three continents. Islam is not, as some imagine in the West, a religion of the sword nor did it spread primarily by means of war. It was only within Arabia, where a crude form of idolatry was rampant, that Islam was propagated by warring against those tribes which did not accept the message of God--whereas Christians and Jews were not forced to convert. Outside of Arabia also the vast lands conquered by the Arab armies in a short period became Muslim not by force of the sword but by the appeal of the new religion. It was faith in One God and emphasis upon His Mercy that brought vast numbers of people into the fold of Islam. The new religion did not coerce people to convert. Many continued to remain Jews and Christians and to this day important communities of the followers of these faiths are found in Muslim lands.
Moreover, the spread of Islam was not limited to its miraculous early expansion outside of Arabia. During later centuries the Turks embraced Islam peacefully as did a large number of the people of the Indian subcontinent and the Malay-speaking world. In Africa also, Islam has spread during the past two centuries even under the mighty power of European colonial rulers. Today Islam continues to grow not only in Africa but also in Europe and America where Muslims now comprise a notable minority.