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.
Those who meditate unceasingly upon the holy and glorious name [of Jesus] in the depths of their heart can sometimes see the radiance of their own spirit-intelligence. For when the mind is profoundly concentrated on this invocation, we feel experientially how it starts burning off all the layers of dirt that normally suffocates the soul.
For the complete fulfillment of its [the intellect's] purpose we should give it nothing but the prayer 'Lord Jesus'...Those who meditate unceasingly upon this glorious and holy name in the depths of their heart can sometimes see the light of their own intellect. For when the mind is closely concentrated upon this name, then we grow fully conscious that the name is burning up all filth which covers the surface of the soul; for it is written: 'our God is a consuming fire' (Deut. 4:24). Then the Lord awakens in the soul a great love for His glory...This is the pearl of great price which a man can acquire by selling all that he has, and so experience the inexpressible joy of making it his own.
If we fervently desire holiness, the Holy Spirit at the outset gives the soul a full and conscious taste of God’s sweetness, so that the intellect will know exactly of what the final reward of the spiritual life consists.
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.
As wax cannot take the imprint of a seal unless it is warmed or softened thoroughly, so a man cannot receive the seal of God's holiness unless he is tested by labors and weaknesses. That is why the Lord says to St. Paul: 'My grace is sufficient for you: for My power comes to its fullness in your weakness'; and the Apostle himself proudly declares: 'Most gladly therefore will I rather glory in my weaknesses, so that the power of Christ may rest upon me' (2 Cor. 12:9).
Abba Ammonas came one day to eat in a place where there was a monk of evil repute. Now it happened that a woman came and entered the cell of the brother of evil reputation. The dwellers in that place, having learnt this, were troubled and gathered together to chase the brother from his cell. Knowing that Bishop Ammonas was in the place, they asked him to join them. When the brother in question learnt this, he hid the woman in a large cask. The crowd of monks came to the place. Now Abba Ammonas saw the position clearly but for the sake of God he kept the secret; he entered, seated himself on the cask and commanded the cell to be searched. Then when the monks had searched everywhere without finding the woman, Abba Ammonas said, 'What is this? May God forgive you!' After praying, he made everyone go out, then taking the brother by the hand he said, 'Brother, be on your guard.' With these words, he withdrew.
One must clean the royal house from every impurity and adorn it with every beauty, then the king may enter into it. In a similar way one must cleanse the earth of the heart and uproot the weeds of sin and the passionate deeds and soften it with sorrows and the narrow way of life, sow in it the seed of virtue, water it with lamentation and tears, and only then does the fruit of dispassion and eternal life grow. For the Holy Spirit does not dwell in a man until he has been cleansed from passions of the soul and body. Only one thing may remain within a man, either the Holy Spirit or the passions. Where the Holy Spirit is, there the passions do not come near, and where the passions are, there the Holy Spirit does not dwell, but rather the evil one.
If anyone thinks that he has love but does not have the same love for all, but distinguishes between persons, separating the lowly from the rich, the infirm from the healthy, a sinner from a righteous man, one far off from one near, one who is an enemy from one who loves you, such love is not perfect, but partial. Actual and perfect love consists in considering everyone and loving them equally, both those who love you and those who hate you. Such love, with which mercy is inseparable, is, in brief, a net for all virtues. It embraces and contains all the commandments of God within itself.
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.
Condemn only yourself, and you will not be condemned at His second and awful coming. From your whole heart remit the sins of whoever sins before you, and your Father who is in heaven will remit your sins.
Let us have recourse to humility on all occasions; for the humble lie prone on the ground, and how can a man fall if he lies on the ground? But a man who stands on a height can easily fall.
If thou, being offended by anything, dost sense that grief and wrath have seized thee, preserve silence, and say naught until unceasing prayer pacifies thine heart.
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.