'Lord Jesus Christ, Son of God, have mercy on me, a sinner.' Let your attention and instruction be centered on this. Walking, eating, standing in church before the beginning of the service, continue with the prayer; on entering and departing keep this prayer on your lips and within your heart. In such a manner, with the invocation of the Name of God you will find peace, you will attain to purity of spirit and body; and the Holy Spirit, the Origin of all good, will make for Himself a dwelling within you and will guide you in all piety and purity.
To more conveniently become accustomed to remembering God, the fervent Christian has a special means, namely, to repeat ceaselessly a brief prayer of two or three words. Mostly this is 'Lord, have mercy.' or 'Lord Jesus Christ, Son of God, have mercy on me, a sinner.' If you have not yet heard of this, then hear it now, and if you have not done it, then begin from this hour to do it.
Let no one think, my brother-Christians, that it is the duty only of priests and monks to pray without ceasing, and not of laymen. No, no; it is the duty of all of us Christians to remain always in prayer. For look what the most holy Patriarch of Constantinople, Philotheus, writes in his life of St. Gregory of Thessalonica. This saint had a beloved friend by the name of Job, a very simple but most virtuous man. Once, while conversing with him, His Eminence said of prayer that every Christian in general should strive to pray always, and to pray without ceasing, as Apostle Paul commands all Christians, 'Pray without ceasing' (I Thessalonians 5:17), and as the prophet David says of himself, although he was a king and had to concern himself with his whole kingdom: 'I foresaw the Lord always before my face' (Psalms 15:8), that is, in my prayer I always mentally see the Lord before me. Gregory the Theologian also teaches all Christians to say God’s name in prayer more often than to breathe. So, my Christian brethren, I too implore you, together also with St. Chrysostom, for the sake of saving your souls, do not neglect the practice of this prayer. Imitate those I have mentioned and follow in their footsteps as far as you can.
Continually say the Prayer [of Jesus] intensely, with zeal, with longing; only thus does one become strong in soul. Avoid idle words by means of all sacrifice, for they weaken the soul and it does not have the strength to struggle.
Just as it is impossible to cross the sea without a boat, so it is impossible to repulse the provocation of an evil thought without invoking Jesus Christ.
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.
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.
The incessant invocation of God's name is a medicine which mortifies not just the passions, but even their influence. Just as the physician puts medications or dressings on a wound that it might be healed, without the patient even knowing the manner of their operation, so also the name of God, when we invoke it, mortifies all passions, though we do not know how that happens.
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.
What should one do so that the mind might be constantly occupied with God? If we do not acquire the three following virtues: love for God and men, continence, and the Prayer of Jesus, then our mind cannot be completely occupied with God. For love makes anger meek, continence weakens fleshly desire, and prayer draws the mind away from thoughts and banishes every hatred and high-mindedness.
Grace abides in us from the time of our holy baptism; but, through our inattention, vanity and the wrong life we lead it is stifled, or buried. When a man resolves to lead a righteous life and is zealous for salvation, the fruit of his whole labor is, therefore, the restoration in force of this gift of grace. It comes to pass in a two-fold manner: first, this gift becomes revealed through many labors in following the commandments; insofar as a man succeeds in following the commandments, this gift becomes more radiant and brilliant. Secondly, it manifests and reveals itself through constant invocation of the Lord Jesus in prayer. The first method is powerful, but the second is more so, so that even the first method gains power through it. Thus, if we sincerely wish to open the seed of grace concealed in us, let us hasten to train ourselves in this latter exercise of the heart, and let us have only this work of prayer in our heart, without forms, without images, till it warms our heart and makes it burn with ineffable love of the Lord.
Whenever we are filled with evil thoughts, we should throw the invocation of our Lord Jesus Christ in their midst. Then, as experience has taught us, we shall see them instantly dispersed like smoke in air. Once the intellect is left to itself again, we can renew our constant attentiveness and our invocation. Whenever we are distracted, we should act in this way.
This prayer should never be absent from you: 'Lord Jesus Christ, Son and Logos of the living God, through the Theotokos and all the Saints, have mercy upon me, Thy sinful and unworthy servant.' (This is the actual Jesus Prayer: 'O LORD JESUS CHRIST, SON OF GOD, HAVE MERCY UPON ME, A SINNER.') Always say this prayer both with your mouth and with your mind, day and night, wherever you may be, whether eating, walking, working, or sitting. Always meditate on it, as it benefits you a great deal, frees you here from every evil, delivers you there from eternal Hell, and renders you worthy of going to Paradise, our heavenly country.
Watchfulness and the Jesus Prayer, as I have said, mutually reinforce each other, for close attentiveness goes with constant prayer, while prayer goes with close watchfulness and attentiveness of intellect.
Please put this commandment into practice. Cultivate love towards the Person of Christ to such an extent that, when you pronounce His name, tears fall from your eyes. Your heart must really burn. Then He will become your teacher. He will be your Guide, your Brother, your Father, and your Elder.
Blessed are those who acquire the habit of this heavenly practice (unceasing prayer in the name of Jesus), for by it they overcome every temptation of the evil demons, as David overcame the proud Goliath. It extinguishes the unruly lusts of the flesh, as the three men extinguished the flames of the furnace. This practice of inner prayer tames passions as Daniel tamed the wild beasts. By it the dew of the Holy Spirit is brought down upon the heart, as Elijah brought down rain on Mount Carmel.
