A great effort and much toil are needed in prayer before we can reach a state in which our mind is no longer troubled, and so attain the inward heaven of the heart where Christ dwells. As St. Paul says, 'Do you not realize that Christ dwells within you, unless you are worthless?' (cf. 2 Cor. 13:5).
Join to every breath a sober invocation of the name of Jesus and the thought of death with humility. Both these practices bring great profit to the soul.
Anger is by nature designed for waging war with the demons and for struggling with every kind of sinful pleasure. Therefore angels, arousing spiritual pleasure in us and giving us to taste its blessedness, incline us to direct our anger against the demons. But the demons, enticing us towards worldly lusts, make us use anger to fight with men, which is against nature, so that the mind, thus stupefied and darkened, should become a traitor to virtues.
And so it often comes about that the life of one burning with love after having sinned is more pleasing to God than a life of innocence that grows languid in its sense of security.
Try to know yourself, your own wickedness. Think on the greatness of God and your wretchedness. Meditate on the suffering of Christ, the magnitude of Whose love and suffering surpass our understanding. Ascribe the good that you do to God alone. Do not think about the sin of a brother but about what in him is better than in yourself.... Flee from glory, honors and praise, but if this is impossible, be sorry that such is your lot. Be benevolent to people of low origin. Be freely and willingly obedient not only to those above you but to those below .... The lowlier we are in spirit, the better we know ourselves, and without humility we cannot see God.
Grace is the food and clothing of the saints. It wakens grief in a man's heart, making him dissatisfied and moving him to seek the reason of this dissatisfaction. Grace gives sorrow and grace comforts; showing us the poverty of all things, it engenders in us a repentant sorrow for having fallen short of the love of God... One who is possessed by such sorrow will always grieve, for he thinks of God's offended love and not of the fear of hell. It is a grief of love.