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.
Monasticism itself is a perpetual labor of conquering passions and uprooting them in order that, being in a pure and immaculate state, one may preserve oneself before the face of God. This, then, is your task! Give your attention to it, and direct all your powers towards it.
Do not neglect the practice of the virtues; if you do, your spiritual knowledge will decrease, and when famine occurs you will go down into Egypt (Genesis 41:57, 46:6).
Do not pray that things may be according to your desires, for they are not always in keeping with the will of God. Better pray as you were taught, saying: ‘Thy will be done’ on me (Matt. vi 10). And ask thus about all things, for He always desires what is good and profitable for your soul, whereas you do not always seek it.
If you believe in a Divine Providence which determines the earthly fate of everyone and the way by which he is to be saved, you must also believe that the disposition of your life is the most suitable for you in working out your salvation.
The kingdom of God is within us when God reigns in us, when the soul in its depths confesses God as its master, and is obedient to Him in all its powers. Then God acts within it as master ‘both to will and to do of his good pleasure’ (Phil. ii. 13). This reign begins as soon as we resolve to serve God in our Lord Jesus Christ, by the grace of the Holy Spirit. Then the Christian hands over to God his consciousness and freedom, which comprises the essential substance of our human life, and God accepts the sacrifice; and in this way the alliance of man with God and God with man is achieved, and the covenant with God, which was severed by the fall and continues to be severed by our willful sins, is re-established. This inner alliance is sealed, confirmed, and given the strength to maintain itself by the power of grace in the divine sacrament of baptism, and for those who have fallen after baptism, in the sacrament of repentance: and afterwards it is constantly strengthened by holy communion. All Christians live thus; and consequently they all bear the kingdom of God within themselves, that is to say they obey God as King and are ruled by God as King.
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.