It may happen that for a certain time a man is illumined and refreshed by God’s grace, and then this grace is withdrawn.  This makes him inwardly confused and he starts to grumble; instead of seeking through steadfast prayer to recover his assurance of salvation, he loses patience and gives up.  He is like a beggar who receives alms from the palace, and feels put out because he is not asked inside to dine with the king.  “Blessed are those who have not seen and yet have come to believe” (John 20.29).  Blessed also are those who, when grace is withdrawn, find no consolation in themselves, but only continuing tribulation and thick darkness, and yet do not despair; but, strengthened by faith, they endure courageously, convinced that they do indeed see him who is invisible.  (St. John of Karpathos)