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.
There is one method which, if practiced with full attention, will seldom allow anything passionate to slip unnoticed into the heart. This is to examine our thoughts and feelings, so as to discover which they tend: towards pleasing God or towards pleasing ourselves.
Even if a person’s sin is not only obvious, but very grievous and comes from a hardened and unrepentant heart, do not condemn him, but raise your eyes to the wondrous and incomprehensible judgments of God; then you will see that many people, formerly full of iniquity, later repented and reached a high degree of sanctity, and that, on the other hand, others, who were on a high level of perfection, fell into a deep abyss. Take care, lest you also suffer this calamity through judging others.
I am a Christian, you say, and content yourself with this. This is the first deceit - transferring to yourself the privileges and promise of Christianity, without any care to root true Christianity into yourself; or to ascribe to yourself that which can only be acquired by your strength and inner worthiness. Explain to yourself that it is illusory to hope in a name, that God can raise a son of Abraham from a stone and can take away your promise at any time if the conditions for participating in them are not soon fulfilled. Mainly, clarify to yourself what it means to be a Christian, unite yourself to this ideal, and you will see just how stable is this buttress to your blindness.
You have no peace from thoughts, which impel you to trouble others, and in turn to be troubled by others. But know, my brother, that if we offend by word or deed, we are thereby ourselves offended a hundredfold. Be longsuffering in all things and refrain from letting your own will enter into anything. Carefully examine your thoughts lest they infect your heart with deadly poison (ill temper) and make you take a gnat for a camel, a pebble for a cliff, and lest you become like a man who has a beam in his own eye but beholds the mote in the eye of another.
This reading with prayer preceding strengthens the soul and gives it strength for the entire day. Doctors say you should not leave the house on an empty stomach. With respect to the soul, this is fulfilled by morning prayer and reading. The soul is fed by them, and sets out on the business of the day nourished.
The kingdom of God is within us when God reigns in us, when the soul in its depths confesses God as its master, and is obedient to Him in all its powers. Then God acts within it as master ‘both to will and to do of his good pleasure’ (Phil. ii. 13). This reign begins as soon as we resolve to serve God in our Lord Jesus Christ, by the grace of the Holy Spirit. Then the Christian hands over to God his consciousness and freedom, which comprises the essential substance of our human life, and God accepts the sacrifice; and in this way the alliance of man with God and God with man is achieved, and the covenant with God, which was severed by the fall and continues to be severed by our willful sins, is re-established. This inner alliance is sealed, confirmed, and given the strength to maintain itself by the power of grace in the divine sacrament of baptism, and for those who have fallen after baptism, in the sacrament of repentance: and afterwards it is constantly strengthened by holy communion. All Christians live thus; and consequently they all bear the kingdom of God within themselves, that is to say they obey God as King and are ruled by God as King.
The root of good inner order is the fear of God. Preserve this fear within you constantly: it will hold everything taut, and will allow no slackness either in physical members or thoughts, creating a vigilant heart and a sober mind, and allowing no bodily torpor or blurring of thought. But one must always remember that success in any aspect of the spiritual life is the fruit of the grace of God. Spiritual life comes entirely from His most Holy Spirit. We have our own spirit but it is void of power. It begins to gain strength only when the grace of God flows in it.
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.
If the Lord delays granting you full victory over your enemies and puts it off to the last day of your life, you must know that He does this for your own good; so long as you do not retreat or cease to struggle wholeheartedly. Even if you are wounded in battle, do not lay down your arms and turn to flight. Keep only one thing in your mind and intention - to fight with all courage and ardor, since it is unavoidable. No man can escape this warfare, either in life or in death. And he who does not fight to overcome his passions and his enemies will inevitably be taken prisoner, either here or yonder, and delivered to death.
Self-esteem is so deeply rooted in us and so firmly enmeshed in us, making us think that we are something, and something not unimportant, that it always hides in our heart as a subtle and imperceptible movement, even when we are sure that we do not trust ourselves and are, on the contrary, filled with complete trust in God alone. In order to avoid this conceit of the heart and act without any self-reliance, led only by your trust in God, take care always to preserve an attitude in which the consciousness and feeling of your weakness always precede in you the contemplation of God's omnipotence, and let both alike precede your every action.
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.
The day will come when you are toiling at self-observation and self-constraint, and the adversary will come up and mumble in your ear, 'This will all happen eventually. You’ve been working hard, now take it easy a little bit!' This is such a tempting suggestion that it does not immediately occur to you that you should counter it, or that it is so bad that however little you give in to it, it will cause such inner disturbance. Indulging yourself is just like a tiny hole in a dam. Once a hole has formed, the dam cannot hold; the water will inevitably destroy it. Indulgence does the same thing inside of us; everything will be dispersed, so it will be necessary to start all over again to restore ourselves. Fear this as your most evil enemy, although he speaks with the sweetest words.
If the main goal of the repentant sinner should be total, light-bearing and blessed communion with God, then the main hindrance to this is the existence of the passions still active and working in him - the virtues being as yet unsealed in him - and the unrighteousness of his powers. Therefore his main work upon conversion and repentance should be the uprooting of the passions and sealing the virtues - in a word, correcting himself.
Christ told His friends, that is, His disciples, to beware of the leaven of the Pharisees and scribes, meaning by leaven their false pretence. For hypocrisy is a thing hateful to God, and abominated by man, bringing no reward, and utterly useless for the salvation of the soul, or rather the cause of its perdition. Though sometimes it may escape detection for a little, yet before long it is sure to be laid bare and bring disgrace upon them, like ill-featured women, when they are stripped of that external embellishment which they had produced by artificial means. Hypocrisy, therefore, is a thing foreign to the character of the saints. That it is impossible for those things that are done and said by us to escape the eye of the Deity, He showed by saying: “There is nothing covered that shall not be revealed; neither hid that shall not be known.” For all our words and deeds shall be revealed at the day of judgment.