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.
At this point the zealous man looks inward, and what do you think he finds there? Ceaseless wandering of thoughts, constant onslaughts from the passions, hardness and coldness of heart, obstinacy and disobedience, desire to do everything according to his own will. In a word, he finds everything within himself in a very bad state. And seeing this, his zeal is inflamed, and he now directs strenuous efforts to the development of his inner life, to controlling his thoughts and the dispositions of his heart. From directions on inner spiritual life he discovers the necessity of paying attention to oneself, of watching over the movements of the heart. In order not to admit to anything bad, it is necessary to preserve the remembrance of God. And so he sets to work to achieve this remembrance. But his thoughts can no more be arrested than the wind; his bad feelings and worthless impulses can no more be evaded than the stench of a corpse; his mind, like a wet and frozen bird, cannot rise to the remembrance of God. What is to be done? Be patient, they say, and go on working. Patience and labor are exercised, but all within remains the same. At last someone of experience is found who explains that all is inwardly in disorder because the forces within are divided: mind and heart each go their own way. Mind and heart must be united; then wandering of thoughts will cease, and you will gain a rudder to steer the ship of your soul, a lever by which to set in movement all your inner world. But how can one unite mind and heart? Acquire the habit of praying these words with the mind in the heart, 'Lord Jesus Christ, Son of God, have mercy upon me'. And this prayer, when you learn to perform it properly, or rather when it becomes grafted to the heart, will lead you to the end which you desire. It will unite your mind with your heart, it will cut off your wandering thoughts, and give you the power to govern the movements of your soul.
Those who meditate unceasingly upon the holy and glorious name [of Jesus] in the depths of their heart can sometimes see the radiance of their own spirit-intelligence. For when the mind is profoundly concentrated on this invocation, we feel experientially how it starts burning off all the layers of dirt that normally suffocates 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.
As the earth, long awaiting moistening and at last receiving it in abundance, suddenly is covered by tender and bright greenery, so also the heart, exhausted by dryness, and afterwards revived by tears, emits from itself a multitude of spiritual thoughts and feelings, adorned by the common flower of humility. The labor of weeping, being inseparable from the labor of prayer, requires the same conditions for success as prayer requires. Prayer needs patient, constant dwelling in itself; weeping requires the same. Prayer needs wearying of the body, and brings about exhaustion of the body; this exhaustion produces weeping, which must be born in the troubling and wearying of the body.
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.
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.
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.
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.
The sun rising over the earth creates the daylight; and the venerable and holy name of the Lord Jesus, shining continually in the mind, gives birth to countless intellections radiant as the sun.
Thus should we weep for the forgiveness of our sins. The words of the bearer of the purple should convince us of this: 'Going they went and wept, casting their seed; but coming they shall come with joyfulness, carrying their sheaves (Ps. 125:6);' as well as the words of St. Isaac the Syrian: 'Moisten your cheeks with the tears of your eyes, that the Holy Spirit may abide in you, and cleanse the filth of your malice. Move your lord with your tears, that He may help you' (homily 68).
This mental prayer is the light which illumines man’s soul and inflames his heart with the fire of love of God. It is the chain linking God with man and man with God. Oh the incomparable blessing of mental prayer! It allows a man constantly to converse with God. Oh truly wonderful and more than wonderful – to be with one’s body among men while in one’s mind conversing with God. Angels have no physical voice, but mentally never cease to sing glory to God. This is their sole occupation and all their life is dedicated to this.
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.
Brethren, let us also occupy yourselves with noetic prayer… and seeking God’s mercy, cry out with a humble heart from morning till night and if possible all night long, saying constantly: 'Lord Jesus Christ, Son of God, have mercy on us.'
God, the Word, made man for the salvation of our race, aware of the exceeding frailty and misery of our nature, hath not even here suffered our sickness to be without remedy. But like a skillful doctor, he hath mixed for our unsteady and sin loving heart the potion of repentance, prescribing this for the remission of sins. For after we have received the knowledge of the truth, and have been sanctified by water and the Spirit, and cleansed without effort from all sin and all defilement, if we should happen to fall into any transgression, there is, it is true, no second regeneration made within us by the Spirit through baptism in the water of the font, and wholly recreating us (that gift is given once for all); but, by means of painful repentance, hot tears, toils and sweats, there is a purifying and pardoning of our offences through the tender mercy of our God. For the fount of tears is also called baptism, according to the grace of the Master.
When you shed floods of tears during prayer, do not exalt yourself for this, as though you were above many others. It is that your prayer has received help from above, so that, having zealously confessed your sins, you may incline the almighty to mercy by your tears.