Ignorance is terrible and more than terrible, a truly palpable darkness (cf. Exodus 10:21). Souls suckled on ignorance are tenebrous, their thought is fragmented, and they are cut off from union with God. Its upshot is inanity, since it makes the whole person mindless and insensate. Waxing gross, it plunges the soul into the depths of hell, where there is every kind of punishment and pain, distress and anguish.
Conversely, divine knowledge is luminous and endlessly illuminating: souls in which it has been engendered because of their purity possess a godlike radiance, for it fills them with peace, serenity, joy, ineffable wisdom and perfect love.
~Nikitas Stithatos
Prayerful Life 