The Phenomenal Growth Of Islam

William H. McNeill quotes "The rise of Islam offers perhaps the most impressive example in world history of the power of words to alter human behavior in sudden, surprising ways."

Lawrence E. Browne in 'The Prospects of Islam,' 1944
Incidentally these well-established facts dispose of the idea so widely fostered in Christian writings that the Muslims, wherever they went, forced people to accept Islam at the point of the sword.