From the oasis cities of Makkah and Al-Madinah in the Arabian desert, the Message of Islam went forth with electrifying speed. Prophet Muhammad (pbuh) started calling his people to Islam with wisdom and beautiful preaching as God commanded him. In the beginning, only few people responded to the Call of the Prophet including rich and poor, slaves and free people. After a long period of torture and persecution by the Makkans, the Prophet and his companions migrated to Al-Madinah and established the first Muslim state. Many people from the Arab tribes out of Al-Madinah accepted Islam and started calling to it among their own tribes. The Prophet sent many letters to leaders and kings in and outside the Arabian Peninsula. During that time Muslims were few and weak, so they were targeted by the pagans a lot and they had to defend themselves. Consequently many military clashes and battles took place between Muslims and the pagans who attacked Al-Madinah more than once. In the end Muslims won the battles, and the Arabian Peninsula was purified from paganism and idolatry.

Outside the Arabian peninsula, Islam was spread in two ways:

1- The contacts between the Muslim traders and callers with non-Muslim peoples. These Muslims presented the facts of Islam to others with wisdom, beautiful preaching and good behaviour. The peoples of East Asia (Indonesia, Malaysia and their neighbours) and sub-Saharan Africa embraced Islam through this way.

It was faith in the One God, the great and logical teachings of Islam that treat all people equally and the kind and gracious behaviour of Muslims 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, and churches and synagogues still exist from the first century.
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. Non-Muslims’ contacts with Muslim minorities and recognition of the truth of Islam through the media and modern ways of communication made Islam the fastest growing religion in the world and particularly in America.

2- The Muslim conquests that took place to stop the threats of the Roman and Persian colonizations, to liberate the Arab countries and to remove the obstacles that deprived those people from knowing the new faith. The conquered peoples found in Islam freedom, tolerance and honour they always sought.

The war between Muslims and the Romans ended with the Romans' defeat in Asia Minor (Turkey). A state of war prevailed until Constantinople was conquered. That conquest led to Eastern Europe and the Balkans.

As for the war with the Persians, despite the participation of the major Persian leaders including Caesar, it ended with the collapse of the Persian state. This paved the way to freedom of religion in those areas. The majority of those peoples chose Islam as their new faith. Some minorities in Persia and other conquered countries, until our days, preserved their religion under the care of the Muslim rule.