Sin, to one who loves God, is nothing other than an arrow from the enemy in battle. The true Christian is a warrior fighting his way through the regiments of the unseen enemy to his heavenly homeland.
Such are the souls of the saints: they love their enemies more than themselves, and in this age and in the age to come they put their neighbor first in all things, even though because of his ill-will he may be their enemy.
Patient endurance kills the despair that kills the soul; it teaches the soul to take comfort and not to grow listless in the face of its many battles and afflictions.
A true Christian is made by faith and love toward Christ. Our sins do not in the least hinder our Christianity, according to the word of the Savior Himself. He deigned to say: not the righteous have I come to call, but sinners to salvation; there is more joy in heaven over one who repents then over ninety righteous ones. Likewise concerning the sinful woman who touched His feet, He deigned to say to the Pharisee Simon: to one who has love, a great debt is forgiven, but from one who has no love, even a small debt will be demanded. From these judgments a Christian should bring himself to hope and joy, and not in the least accept an inflicted despair. Here one needs the shield of faith.
Not every man can be trusted when giving advice to those who seek it. We can trust only him who has received from God the grace of discrimination and who ... has acquired through great humility and long practice of the virtues an intellect blessed with spiritual insight. Such a man is in a position to advise, not everyone, but at least those who seek him out voluntarily and who question him by their own choice; for he has learned things in their true order.