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.
Cultivate the Jesus Prayer and a time will come when your heart will leap with joy, just as it does when you are about to see a person who you love very much.
As soon as you wake up in the morning, pray for a while, saying: 'Lord Jesus Christ, Son of God, have mercy upon me.' Then your first work should be to shut yourself in your own heart, as if taking up position in an arena. Having established yourself there, bring yourself to the consciousness and feeling that your enemy and the passionate urge against which you struggle at the moment are already there, on your left, ready for immediate attack; therefore rouse against them a firm resolve to conquer or die, but never to submit. Realize also that on your right there stands, invisibly present, your Commander, our Lord Jesus Christ, with His Holy Mother and a host of holy Angels, with Archangel Michael at their head, ready to come to your aid. So take heart and be of good cheer.
Because the nous can get tired by the reciting of all the words of the Jesus Prayer, it is necessary to make it shorter: 'Lord Jesus Christ, have mercy on me.' Or, 'Lord have mercy on me.' Or, 'Lord Jesus.' As the Christian progresses in the work of the Jesus Prayer, he can decrease the words. He can even sometimes insist on the word 'Jesus,' which he says repeatedly (Jesus, Jesus, Jesus, my Jesus)--a wave of calmness and joy rises in him. He should remain in this sweetness which appears and not stop the prayer, even if his usual rule of prayer is finished. He should seize and keep this warmth of his heart and take advantage of this gift of God! For it is a great gift which God sends from on high. The warmth of the heart helps the nous effectively to be fixed on the words of the Jesus Prayer ... If one wants to spend all day in prayer, he should follow the recommendation of the Holy Fathers. He should pray for an hour, read for an hour and then again spend an hour in prayer. When he is engaged in manual work too, he should try to say the Jesus Prayer.
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.
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.
All Christians, clergy, laity and monks, when rising from sleep must first think of and remember Christ. They must offer this remembrance to Christ as a sacrifice and first-fruits of every thought (Hebrews 13:15). For we must remember, before every thought, Christ Who saved us and has loved us so greatly, for we are, and are called, 'Christians'. We put him on by divine Baptism (Gal. 3:27), and we were sealed with His Chrism. We have partaken, and do partake, of His holy Body and Blood. We are His members (I Cor. 12:27) and His temple (II Cor. 6:16). Him do we put on, and He dwells in us. For this reason we are obliged to love Him and remember Him always. Wherefore, let everyone devote time, according to his ability, and have a certain amount of this prayer as an obligation. And this suffices concerning this matter, for this is a sufficient amount of instruction for those who seek concerning it.
In the grim struggle with the invisible enemies of our salvation, the supreme weapon is the prayer of Jesus. `All the nations' - the vociferous and wily demons are called nations - `surround me,' says David, `and in the name of the Lord I repulsed them. They encircled and surrounded me like bees, and they burnt like fire among thorns; and in the name of the Lord I repulsed them' (Ps. 117:10-12). With the name of Jesus flog the foes, because there is no stronger weapon in heaven or earth.
Join to every breath a sober invocation of the name of Jesus and the thought of death with humility. Both these practices bring great profit to the soul.
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.
The power given by the Lord to His seventy disciples is given to all Christians (Mk. 16:17). Use it, Christian! With the name of Jesus cut off their heads, that is the first appearances of sin in our thoughts, fancies and feelings. Destroy within you the devil's rule over you; destroy all his influence over you; acquire spiritual freedom. The foundation for your struggle is the grace of holy baptism; your weapon is prayer in the name of Jesus.
When the attention of the mind is fixed in the heart it is possible to control what happens in the heart, and the battle against the passions assumes a rational character. The enemy is recognized and can be driven off by the power of the Name of Christ.
At first it may appear very difficult to you, but be assured, as it were from Almighty God, that this very name of our Lord Jesus Christ, constantly invoked by you, will help you to overcome all difficulties, and in the course of time you will become used to this practice and will taste how sweet is the name of the Lord. Then you will learn by experience that this practice is not impossible and not difficult, but both possible and easy. This is why St. Paul, who knew better than we the great good which such prayer would bring, commanded us to pray without ceasing. He would not have imposed this obligation upon us if it were extremely difficult and impossible, for he knew beforehand that in such case, having no possibility of fulfilling it, we would inevitably prove to be disobedient and would transgress his commandment, thus incurring blame and condemnation. The Apostle could have had no such intention.
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.
Pre-eminence belongs to the Jesus prayer because it unites the soul with our Lord Jesus, and the Lord Jesus is the only door to union with God, which is the aim of prayer.
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.
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.