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.
For not only are spiritual riches and heavenly gifts received from God, but earthly and material possessions also proceed from His bounty, that He may be justified in requiring an account of those things which He has not so much put in our possession, as committed to our stewardship. God’s gifts, therefore, we must use properly and wisely, lest the material for good work should become an occasion for sin.
If Nabuzardan, the court cook of the King of the Babylonians, had not gone to Jerusalem, then the Temple would not have burned (cf. 2 Kings 24), That is to say, a person’s mind is not attacked by the flames of carnal pleasures, if a person is not conquered by gluttony.
But a sober and prudent man who desires to be saved, when he sees from what it is that he suffers harm, carefully preserves himself from evil remembrances, is not drawn into passionate thoughts, avoids meetings and conversations with those for whom he feels attraction and avoids every occasion for sin, fearing lest he himself ignite a fire within himself. This is the warfare which proceeds from one’s own lust, which a man brings on himself
The nature then of Christ's teaching is attested by His own holy statements: that they who wish to arrive at eternal blessedness may understand the steps of ascent to that high happiness. 'Blessed,' He saith, 'are the poor in spirit, for theirs is the kingdom of heaven.' It would perhaps be doubtful what poor He was speaking of, if in saying 'blessed are the poor' He had added nothing which would explain the sort of poor: and then that poverty by itself would appear sufficient to win the kingdom of heaven which many suffer from hard and heavy necessity. But when He says 'blessed are the poor in spirit,' He shows that the kingdom of heaven must be assigned to those who are recommended by the humility of their spirits rather than by the smallness of their means.
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
Compunction comes when you consider how much you have grieved God Who is so good, so sweet, so merciful, so kind, and entirely full of love; Who was crucified and suffered everything for us. When you meditate on these things and other things the Lord has suffered, they bring compunction.
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
He who wishes to purify his faults purifies them with tears, and he who wishes to acquire virtues, acquires them with tears; for weeping is the way the Scriptures and our Fathers give us, when they say 'Weep!' Truly, there is no other way than this.
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.
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).
There is no greater love than that a man lays down his life for his neighbor. When you hear someone complaining and you struggle with yourself and do not answer him back with complaints; when you are hurt and bear it patiently, not looking for revenge; then you are laying down your life for your neighbor.