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.
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.
A small affliction borne for God's sake is better [before God] than a great work performed without tribulation, because affliction willingly borne brings to light the proof of love.
The angel who is always near us is by nothing so distressed and made indignant as when, without being constrained by some necessity, we deprive ourselves of the ministration of the Holy Mysteries and of reception of Holy Communion, which grants remission of sins. For at that hour the priest offers up the sacrifice of the Body of Him Who gives us life, and the Holy Spirit descends and consecrates the Body and Blood and grants remission to creation. The Cherubim, the Seraphim, and the angels stand with great awe, fear, and joy. They rejoice over the Holy Mysteries while experiencing inexpressible astonishment. The angel who is always by us is consoled, because he also partakes in that dread spectacle and is not deprived of that perfect intercourse.
It is just as shameful for lovers of the flesh and the belly to search out spiritual things as it is for a harlot to discourse on chastity. A body suffering grave illness shuns fatty foods and abhors them; and likewise, a mind occupied with worldly affairs cannot approach the inquiry into things of God. A fire cannot be ignited with wet wood, nor can the divine fervor be kindled in a heart that loves ease.
It is not possible for any man to draw near to Christ without tribulation, and without afflictions his righteousness cannot be preserved unchanged. If he puts an end to the labors that make righteousness increase, he will put an end to that which guards it, and his righteousness will be like unguarded treasure. And he will be like a gladiator surrounded by enemy ranks and stripped of his weapons, like a ship bereft of its sails and tackle, and like a garden deprived of its source of water.
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.
Not every man is wakened to wonder by what is said spiritually and has great power concealed in it. A word concerning virtue has need of a heart unbusied with the earth and its converse.
To wage war only with the sins that make their appearance as actual deeds would be just as unsuccessful as cutting down weeds in a garden instead of digging them up at the root and throwing them out. Sins appear as inevitable outgrowths from their roots, the passions of the soul.
Not he is chaste in whom shameful thoughts stop in time of struggle, work and endeavor, but he who by the trueness of his heart makes chaste the vision of his mind not letting it stretch out towards unseemly thoughts.
It is impossible for the soul to be liberated from turbulent thoughts without the virtue of non-possessiveness. And without peace of the bodily senses it is impossible for the soul to have a peaceful intellect. And if it does not come into temptations it will not acquire wisdom of the Holy Spirit. And without laborious and persistence in reading, it will not come to the discernment of thoughts. And without the stillness of thoughts, the intellect cannot move to seek the hidden mysteries of God.
