Through repentance a person receives back that knowledge which was given to him as a pledge in baptism…. Repentance arises in a person through the activity of divine grace in the soul. It begins when God bestows on us a consciousness of our own sins. This consciousness penetrates into our thoughts as God sees to it that we suffer multifarious trials. Perceiving one’s own sins, Isaac claims, is more important than performing miracles or having supernatural mystical visions, for with this awareness the way of repentance begins. And repentance itself is higher than many other virtues.
Met. Hilarion Alfevev writing in The Spiritual World of Isaac the Syrian