St. Peter of Damascus teaches, 'When joy comes, represent sorrow to yourself; and when you are encompassed by sorrow, try to awaken joy.' Thus you will be safeguarded both against deception and against despair.
The deadly wound consists of every sin that is not repented and confessed, and of falling into despair. This depends on our choice and will. If we do not yield ourselves to the pit of carelessness and despair the devils cannot prevail over us. Even when we have been wounded, if we so wish we may through fervent penitence become more courageous and skillful fighters.
Baptism does not take away our free will or freedom of choice, but gives us the freedom no longer to be tyrannized by the devil unless we choose to be. After baptism it is in our power either to persist willingly in the practice of the commandments of Christ, into whom we were baptized, and to advance in the path of His ordinances, or to deviate from this straight way and fall again into the hands of our enemy...
The only thing God requires of us is that we do not sin. But this is achieved, not by acting according to the law, but by carefully guarding the divine image in us and our supernal dignity. When we thus live in our natural state, wearing the resplendent robe of the Spirit, we dwell in God and God dwells in us. Then we are called gods by adoption and sons of God, sealed by the light of the knowledge of God.
As earth thrown over it extinguishes a fire burning in a stove, so worldly cares and every kind of attachment to something, however small and insignificant, destroy the warmth of the heart which was there at first.
Take care never to receive Communion while you have anything against anyone, even if this is only a hostile thought. Not until you have brought about reconciliation through repentance should you communicate, [receive the Mysteries]. But you will learn this, too, through prayer.
As for uprooting your passions, begin with self-reproach and with awareness of your own weaknesses; and consider yourself to be deserving of afflictions.
As a blacksmith can do nothing without the help of fire, however skilled he may be in wielding his tools, so a man should do everything he can on his side to purify his heart, using virtues as tools for this purpose; but without fire of the Spirit, everything he does will remain inactive and useless for his aim, for by itself what he does is powerless to cleanse the soul of its dirt and foulness.
God seeks nothing else from us men except that we do not sin; this alone. But this is not a work of law; it is rather a careful guarding of the image and dignity from above. In these things, affirmed in our nature and bearing the radiant garment of the Spirit, we shall abide in God and He in us. We shall be called good, and sons of God by adoption, marked in the light of our knowledge of God.