We should not miss any chance to us to say the Jesus Prayer. We must not let our mind wander in vain things. In saying the Jesus Prayer one's mind finds rest and joy. It is like small children who for the whole day run around, shouting and playing and hitting each other. But the one thing that gives them rest and great joy is when at night they find themselves in their mother's arms. This way also one's mind instead of being scattered about, out to be devoted to mental prayer.
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
When a man has been sufficiently illumined, however, to perceive his own faults, he never ceases mourning for himself and for all men, seeing God’s great forbearance and what sins we in our wretchedness have committed and still persist in committing. As a result of this he becomes full of gratitude, not daring to condemn anyone, shamed by the profusion of God’s blessings and the multitude of our sins. Thereupon he joyfully renounces everything in his own will that is counter to God, and he watches over his own senses, so as to prevent them from doing anything beyond what is unavoidably needed.
If a king wanted to take possession of his enemy's city, he would begin by cutting off the water and the food and so his enemies, dying of hunger, would submit to him. It is the same with the passions of the flesh; if a man goes about fasting and hungry the enemies of his soul grow weak.
Nothing so abets our secret destruction as conceit and self-satisfaction, or so cuts us off from God and provokes our chastisement at the hands of other men as grumbling, or so disposes us to sin as a disorderly life and talkativeness.
One time St. Nicodemos, on a feast day, was walking toward the Great Lavra (on Mt Athos). On his way he came across a kellion where he spent the night. At midnight he saw an elder and his accompanying monks entering the church. He secretly went in also, and there he saw the elder and his subordinate monks uttering the Jesus Prayer ('Lord Jesus Christ, Son of God, have mercy on me'), sometimes in a kneeling position, sometimes standing up. And at the time of the Holy Communion, he saw all their faces shining only a little less dimly than the sun.
We ought all of us always to give thanks to God for both the universal and the particular gifts of soul and body that He bestows on us. The universal gifts consist of the four elements and all that comes into being through them, as well as all the marvelous works of God mentioned in the divine Scriptures. The particular gifts consist of all that God has given to each individual. These include wealth, so that one can perform acts of charity; poverty, so that one can endure it with patience and gratitude; authority, so that one can exercise right judgment and establish virtue; obedience and service, so that one can more readily attain salvation of soul; health, so that one can assist those in need and undertake work worthy of God; sickness, so that one may earn the crown of patience; spiritual knowledge and strength, so that one may acquire virtue; weakness and ignorance, so that, turning one's back on worldly things, one may be under obedience in stillness and humility; unsought loss of goods and possessions, so that one may deliberately seek to be saved and may be helped when incapable of shedding all one's possessions or even of giving alms; ease and prosperity, so that one may voluntarily struggle and suffer to attain the virtues and thus become dispassionate and fit to save other souls; trials and hardship so that those who cannot eradicate their own will may be saved in spite of themselves, and those capable of joyful endurance may attain perfection.
The more a man struggles to do good, the more fear grows in him, until it shows him his slightest faults, those which he thought of as nothing while he was still in the darkness of ignorance.
The late Athonite Father Tikhon used to say: The prayer, 'Lord Jesus have mercy on us' is worth one hundred drachmas, but 'Glory to God' is word one thousand. Glorifying God is more valuable than anything else, because in the first instance, people often say the Jesus Prayer when needing something; but when one glorifies God in the midst of suffering, it is an ascesis.
It is as necessary for a man to say the Jesus Prayer as it is for a ship in danger to send out steadily the S.O.S. signal: Lord Jesus Christ have mercy on me.
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.
Whoever is experienced in the spiritual interpretation of Scripture knows that the simplest passage is of a significance equal to that of the most abstruse passage, and that both are directed to the salvation of man.