"Consider how men for generations have been blindly imitating their fathers ..."

"It is evident that the changes brought about in every Dispensation constitute the dark clouds that intervene between the eye of man’s understanding and the Divine Luminary which shineth forth from the day spring of the Divine Essence. Consider how men for generations have been blindly imitating their fathers, and have been trained according to such ways and manners as have been laid down by the dictates of their Faith. Were these men, therefore, to discover suddenly that a Man, Who hath been living in their midst, Who, with respect to every human limitation hath been their equal, had risen to abolish every established principle imposed by their Faith—principles by which for centuries they have been disciplined, and every opposer and denier of which they have come to regard as infidel, profligate and wicked,—they would of a certainty be veiled and hindered from acknowledging His truth. Such things are as “clouds” that veil the eyes of those whose inner being hath not tasted the Salsabíl 1 of detachment, nor drunk from the Kawthar 2 of the knowledge of God. Such men, when acquainted with those circumstances, become so veiled that, without the least question, they pronounce the Manifestation of God as infidel, and sentence Him to death. You must have heard of such things taking place all down the ages, and are now observing them in these days."

-Bahá'u'lláh, Gleanings From the Writings of Bahá’u’lláh, XIII, p. 26

1. Salsabíl: Literally, softly flowing.  A fountain of Paradise.
2. Kawthar: A river of Paradise from which all the others flow.  Part of its waters are led into a great lake on the shores of which the souls of the faithful rest when they have crossed the terrible bridge which is laid over the midst of Hell.