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.
Bring before your eyes the blessings, whether physical or spiritual, conferred on you from the beginning of your life down to the present, and call them repeatedly to mind in accordance with the words: 'Forget not all His benefits' (Ps. 102:2). Then your heart will readily be moved to the fear and love of God, so that you repay Him, as far as you can. by your strict life, virtuous conduct, devout conscience, wise speech, true faith and humility - in short, by dedicating your whole self to God. When you are moved by the recollection of all these blessings which you have received through God's loving goodness, your heart will be spontaneously wounded with longing and love through this recollection or, rather, with the help of divine grace.
Those who have truly decided to serve the Lord God must train themselves in the remembrance of God and in unceasing prayer to Jesus Christ, saying mentally: 'Lord Jesus Christ, Son of God, have mercy on me, a sinner.' Through such activity, and by guarding oneself from distraction, and with the preservation of peace in one's conscience, it is possible to draw near to God and to be united with Him. For, according to the words of St. Isaac the Syrian, 'Except for unceasing prayer we cannot draw near to God.'
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.
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.
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.
Give thanks to God for all things, because thanksgiving is intercession before God for our weakness. Judge yourself always and in everything as a sinner and as one seduced - and so God will not judge you; be humble in everything and you will receive grace.
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.'
Continuity of attention produces inner stability; inner stability produces a natural intensification of watchfulness; and this intensification gradually and in due measure gives contemplative insight into spiritual warfare. This in its turn is succeeded by persistence in the Jesus Prayer and by the state that Jesus confers, in which the intellect, free from all images, enjoys complete quietude.
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.
Man's chief aim should be to find God. In finding God, he finds true happiness. The interior prayer we have been discussing [the Prayer of Jesus] leads man to Him. We can never thank God sufficiently for revealing Himself to us. We can never even thank Him enough for the other goods He bestows upon us. God need not have created man: He had hosts of angels. Yet He created man and countless marvelous things for him.
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.
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.