Islam approached the whole Peninsula so rapidly because of the true spiritual, social, political and educational teachings of Islam. Great sympathetic attitude, unbeaten determination and restless hard work of both Prophet Muḥammad (peace and blessings of Allah be upon him) and his followers were the key sources for this fastest ever intellectual missionary progress. The power was utilized by them, on unavoidable occasions, only to extend the boundaries of their state, but never to compel the conquered ones towards Islam. This historical reality is no more unknown to the modern orientalists. Yet a good number of them, including William Muir, Washington Irving, George Sale and many others propagated that the Muslims promoted their religion and widened their state altogether by force of sword.
They have well been answered logically and historically by their fellow orientalists who not only rejected all such accusations on the missionary role of Muslims, but also acknowledged Muḥammad (peace and blessings of Allah be upon him) a moral symbol for Humanity. They maintain that Islam went on its spiritual growth even in the political degradation and economic weakness of its Empire. They proved that the Islamic teachings not only influenced the public of the lands conquered by the Muslims but they also proselytized the Non-Muslim conquerors of the Muslim territories. As None of the orientalists except Thomas Arnold has written such a comprehensive book for this sole purpose to attest thoroughly the extension of Islam in all over the world, and the answers of the orientalists quoted in this paper are scattered in their individual general works on Islam or its Prophet(peace and blessings of Allah be upon him), therefore this research paper is written to collect about all types of the objections and the justifying defensive statements of the orientalists on the spread of Islam on one place and to present a precise conclusion by analysing and evaluating them in the light of the authentic history .
Keywords: Spread of Islam, spiritual teachings, sympathetic behavior, missionary role, historical facts, and truthful orientalists.