We must first purge ourselves of the vicious materiality prompted in us by the demons–this is the stage of purification; then, through the stage of illumination, we must make our spiritual eyes lucid and ever light-filled, and this is accomplished by means of the mystical wisdom hidden in God. In this way we ascend to the cognition of sacred knowledge, which through the intelligence imparts things new and old to those who have ears to hear.
Then we in turn must pass on to others images and intimations of this knowledge, conveying its hidden meaning to the purified while withholding it from the profane, least holy things be given to dogs, or the pearl of the Logos be cast before swine-like souls that would defile it (cf. Matthew 7:6).
~Nikitas Stithatos
Prayerful Life 