While we are looking to the passions for fulfillment, our desire for the infinite is doomed to be frustrated. Once we realize this, we discover that God alone can satisfy the need which is basic to our nature.
Origen has described a striking vision of the soul plumbing the depths of evil by experiencing the horror of excess; after actually dying, having journeyed through the infernal regions, it eventually realizes that evil has its limitations, that one can be surfeited with it to the point of utter boredom. [I can vouch for this. -ed] Then God is revealed as alone inexhaustible, to whom everyone, even Satan, will turn in the end...
Metanoia, the complete turning round in a person's heart of hearts, is not an attempt to achieve some superficial mental improvement by an effort of will , to overcome some fault or vice. It is first and foremost the utter trusting in Christ who gives himself up to death, hell, and separation for us, for me; to the death which I have caused, to the hell which I create, and in which I make others and myself life, to the separation which is my condition and my sin. By enduring them, he has made death, hell, and torment the door of repentance and new life. Then we discover something we never dared hope for, that our hellish autonomy has been breached by sin, death, and despair, that these have opened us to the mercy of the living God. Then the heart of stone becomes a heart of flesh, the stone which sealed the fountain of life in our heart is shattered; then gush forth the tears of repentance and wonderment, washing us in the waters of baptism, the great waters sanctified by Christ in the beginning, in which we are purified and recreated by the Spirit. -Olivier Clement