... the cities of men’s hearts...

Know thou that We have annulled the rule of the sword, as an aid to Our Cause, and substituted for it the power born of the utterance of men. Thus have We irrevocably decreed, by virtue of Our grace. Say: O people! Sow not the seeds of discord among men,  and refrain from contending with your neighbor, for your Lord hath committed the world and the cities thereof to the care of the kings of the earth, and made them the emblems of His own power, by virtue of the sovereignty He hath chosen to bestow upon them. He hath refused to reserve for Himself any share whatever of this world’s dominion. To this He Who is Himself the Eternal Truth will testify. The things He hath reserved for Himself are the cities of men’s hearts, that He may cleanse them from all earthly defilements, and enable them to draw nigh unto the hallowed Spot which the hands of the infidel can never profane. Open, O people, the city of the human heart with the key of your utterance. Thus have We, according to a pre-ordained measure, prescribed unto you your duty.
 Gleanings From the Writings of Bahá’u’lláh