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.
I said to him, 'My sweet and good father, where do you receive the Eucharist on the Sabbath and the Lord's Day?' He said to me, 'Every Sabbath and every Lord's Day, an angel comes to me and gives me the Eucharist. And blessed is everyone who lives as a citizen in the desert on account of God and sees no human being -- He brings the Eucharist to them and comforts them. If they desire to see anyone, they are taken up to heavenly heights and they see them. They greet them and the hearts are filled with light. They rejoice in the Spirit and are glad in the good things they will never lack. When they see them, they are comforted, and they completely forget the afflictions that have been theirs. Afterwards they return to their places, and they are comforted for a long time, as though they had been removed to another world. Because of the great joy they have seen, they do not remember that this world even exists.'
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).
Observe at the same time that the mystery consists in the very office of humility, for Christ says: 'If I, your Lord and Master, have washed your feet; how much more ought you to wash one another's feet.' For, since the Author of Salvation Himself redeemed us through His obedience, how much more ought we His servants to offer the service of our humility and obedience.
God's Scripture gives proof in numerous passages that man must undergo many disturbances in this life; and also that many consolations are at hand. With these, a spirit of sufficient vigor and awareness of the right should overcome present discomforts and look to those things that promise everlasting joy.
But there is hardly anything more serious than to be joined in marriage to a stranger (i.e., to an unbeliever), where the instigations both of lustful appetite and of disharmony and the shameful crimes of sacrilege are welded together. For if marriage itself needs to be sanctified by the priestly veil and blessing, how is it possible to speak of a marriage where there is no agreement in faith?
Exercise patience out of love for your fellow man. Exercise patience in order to benefit your soul. For if you do not take your soul into consideration, you lose your patience.
Patience reigns quietly and fruitfully in the life of the man who does not harm or endanger anyone, who is content with little and is obedient to the commandments of the Heavenly Father.
Do you wish God to hear your prayer immediately, brother? When you lift your hands up to heaven, pray first of all, with your heart, for your enemies and God will grant you speedily whatever else you request.
If you wish to be delivered from shameful passions, do not behave with anyone familiarly, especially with those toward whom your heart is inclined by a lustful passion; through this you will be delivered also from vainglory. For in vainglory is involved the pleasing of men, in the pleasing of men is involved familiarity of behavior, and familiarity of behavior is the mother of all passions.
Do you wish God to hear your prayer immediately, brother? When you lift your hands up to heaven, pray first of all, with your heart, for your enemies and God will grant you speedily whatever else you request.
He stands, then - but not alone, for before Him go angels, saying: 'Lift up the gates, O ye the princes.' What gates? Even those of which the Psalmist sings in another place also: 'Open to me the gates of righteousness.' Open, then, thy gates to Christ, that He may come into thee - open the gates of righteousness, the gates of chastity, the gates of courage and wisdom. Believe the message of the angels: 'Be ye lifted up, ye everlasting doors, and the King of Glory shall come in, the Lord of Sabaoth.'
Give thanks to God for all things, because thanksgiving is intercession before God for our weakness. Judge yourself always and in everything as a sinner and as one seduced - and so God will not judge you; be humble in everything and you will receive grace.