"The believer's greatest argument is his face.

True religion lights up the face; false religion fills it with insecurity, rage and suspicion. This is perceptible not only to insiders, but to anyone who maintains some connection with unsullied primordial human nature in his heart. The early conversions to Islam often took place among  populations that had no access to the language of the Muslims who now lived among them; but they were no less profound in consequence. Religion is ultimately a matter of personal transformation, and no amount of missionary work will persuade people - with the occasional exception of the disturbed and the desperate - unless our own transformation is complete enough to be able to transform others.

— Tim Winter (Abdal Hakim Murad), "Tradition or Extradition?"