Nothing so abets our secret destruction as conceit and self-satisfaction, or so cuts us off from God and provokes our chastisement at the hands of other men as grumbling, or so disposes us to sin as a disorderly life and talkativeness.
Continually say the Prayer [of Jesus] intensely, with zeal, with longing; only thus does one become strong in soul. Avoid idle words by means of all sacrifice, for they weaken the soul and it does not have the strength to struggle.
Bring before your eyes the blessings, whether physical or spiritual, conferred on you from the beginning of your life down to the present, and call them repeatedly to mind in accordance with the words: 'Forget not all His benefits' (Ps. 102:2). Then your heart will readily be moved to the fear and love of God, so that you repay Him, as far as you can. by your strict life, virtuous conduct, devout conscience, wise speech, true faith and humility - in short, by dedicating your whole self to God. When you are moved by the recollection of all these blessings which you have received through God's loving goodness, your heart will be spontaneously wounded with longing and love through this recollection or, rather, with the help of divine grace.
Do not judge one another, for you transgress the evangelical law, and 'every transgression and disobedience received a just retribution' (Heb. 2:2). 'Who are you to pass judgment on the servant of another?' (Rom. 14:4). Do you not know that the one who passes judgment goes astray through pride, and that everyone who exalts himself will be humbled (Luke 14:11) by the Lord, when temptation seizes him?
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.