To act 'according to one’s strength' means to use a little less than necessary both of food, and drink, and sleep... As for food, restrain yourself when you wish to eat a little more, and in this way you will always make use of it moderately.
Acquire humility, which scorches the demons, obedience, which opens the door for the Son of God to enter a man, faith which saves a man, hope which makes him unashamed; and love which lets not a man fall away from God.
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.
Concerning fasting, do not grieve, as I have said to you before: God does not demand of anyone labors beyond his strength. And indeed, what is fasting if not a punishment of the body in order to humble a healthy body and make it infirm for passions, according to the word of the Apostle: 'When I am weak, then am I strong' (II Corinthians 12:10).
Do not pray for the fulfillment of your wishes, for they may not accord with the will of God. But pray as you have been taught, saying: 'Thy will be done in me' (Luke 22.42). Always entreat Him in this way, that His will be done. For He desires what is good and profitable for you, whereas you do not always ask for this. Often when I have prayed, I have asked for what I thought was good, and persisted in my petition, stupidly importuning the will of God, and not leaving it to Him to arrange things as He knows is best for me, But when I have obtained what I asked for, I have been very sorry that I did not ask for the will of God to be done, because the thing turned out not to be as I thought.
Watch constantly, learning to understand God's law, for this warms the heart with heavenly fire. Guard your lips from the idle word, or empty talk, lest the heart gets used to evil words.
Leave off all evasions, bend your neck to humility and obedience, and you will receive mercy. If you practice with humility and obedience what you hear from the fathers, God will grant you His blessed help not only in the work you are doing, but will make all your works successful, for He protects the path of those who fear Him and watches their progress.
My brother, the passions are afflictions; and so the Lord does not excommunicate us because of them, but He says: 'Call upon me in the time of affliction; and I will deliver thee, and thou shalt glorify me'. Therefore, when beset by any kind of passion, there is nothing more useful than to call upon the Name of God. All we can do, weak as we are, is to flee for refuge to the Name of Jesus. For the passions, being demons, retreat if this Name is invoked.
