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.
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.
My brother, the passions are afflictions; and so the Lord does not excommunicate us because of them, but He says: 'Call upon me in the time of affliction; and I will deliver thee, and thou shalt glorify me'. Therefore, when beset by any kind of passion, there is nothing more useful than to call upon the Name of God. All we can do, weak as we are, is to flee for refuge to the Name of Jesus. For the passions, being demons, retreat if this Name is invoked.
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.
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.
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.
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.
Prayer is the mind's dialogue with God, in which words of petition are uttered with the intellect riveted wholly on God. For when the mind unceasingly repeats the name of the Lord and the intellect gives its full attention to the invocation of the divine name, the light of the knowledge of God overshadows the entire soul like a luminous cloud.
Use your body, I beseech you, with moderation. Remember, with this body you will be raised from death when you come to be judged. Perhaps you have some doubt whether this could happen. If so, reflect in detail on what has already happened with your own self. Tell me, where were you a hundred years ago? Cannot the Creator who gave existence to a person that did not exist bring to life again to a person that did exist but is now dead? Every year He makes the corn spring to life that had withered and dies after it was sown. Do you suppose that He who raised Himself from the dead for our sake will have difficulty in raising us to new life? Or look at the trees. For a number of months they remain without fruit, even without leaves. But once the winter is past, they become green all over, new, as if risen from the dead. With better reason, and with greater ease shall we be called to new life. Do not listen to those who deny the resurrection of the body. Isaiah testifies: ‘The dead shall live again: the bodies of those who have died shall live.’ (Isa. 26:19) And according to the word of Daniel, ‘Many of those who sleep beneath the earth shall awaken, some to life eternal, the rest to eternal ruin.’ (Dan. 12:2)
Let us work with the body and pray with the soul. Let our outer man perform his bodily tasks, and let the inner man be entirely dedicated to the service of God, never abandoning this spiritual practice of mental prayer, as Jesus, God and Man, commanded us, saying: 'But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret' (Matthew 6:6).The closet of the soul is the body; our doors are the five bodily senses. The soul enters its closet when the mind does not wander hither and thither, roaming among things and affairs of the world, but stays within, in our heart. Our senses become closed and remain closed when we do not let them be attached to external sensory things, and in this way our mind remains free from every worldly attachment, and by secret mental prayer unites with God its Father. 'And thy Father which seeth in secret shall reward thee openly,' adds the Lord. God who knows all secret things sees mental prayer and rewards it openly with great gifts. For that prayer is true and perfect which fills the soul with Divine grace and spiritual gifts. As chrism perfumes the jar the more strongly the tighter it is closed, so prayer, the more fast it is imprisoned in the heart, abounds the more in Divine grace.
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.
Those who have truly decided to serve the Lord God should practice the remembrance of God and uninterrupted prayer to Jesus Christ, mentally saying: Lord Jesus Christ, Son of God, have mercy on me, a sinner.