Sin, to one who loves God, is nothing other than an arrow from the enemy in battle. The true Christian is a warrior fighting his way through the regiments of the unseen enemy to his heavenly homeland.
If someone should ask: how am I to pray?, the answer is very simple: fear God. Experience of the fear of God arouses attention and consciousness in the heart and forces it to stand with devotion before God.
If you examine your life well, you will find many instances when God showed His unmistakable mercy to you. Trouble was brewing, but it passed you by for some reason. God delivered you. Acknowledge these and thank God, Who loves you.
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 day will come when you are toiling at self-observation and self-constraint, and the adversary will come up and mumble in your ear, 'This will all happen eventually. You’ve been working hard, now take it easy a little bit!' This is such a tempting suggestion that it does not immediately occur to you that you should counter it, or that it is so bad that however little you give in to it, it will cause such inner disturbance. Indulging yourself is just like a tiny hole in a dam. Once a hole has formed, the dam cannot hold; the water will inevitably destroy it. Indulgence does the same thing inside of us; everything will be dispersed, so it will be necessary to start all over again to restore ourselves. Fear this as your most evil enemy, although he speaks with the sweetest words.
In preparing for battle, however, do not think that you will always be victorious. Often there will be only hardship that will bring nothing but affliction... Provide yourself with only one thing, strong courage: no matter what happens, stay with what you have begun... No matter how life goes, whatever successes and failures there are, you should give all of this over to God's will.
We ought to learn the virtues through practicing them, not merely through talking about them, so that by acquiring the habit of them we do not forget what is of benefit to us. 'The kingdom of God,' St. Paul says, 'resides not in words but in power' (I Cor. 4:20). For he who tries to discover things through actual practice will come to understand what gain or loss lies in any activity that he pursues.
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.
Endurance is like an unshakeable rock in the winds and waves of life. However the tempest batters him, the patient man remains steadfast and does not turn back; and when he finds relief and joy, he is not carried away by self-glory: he is always the same, whether things are hard or easy, and for this reason, he is proof against the snares of the enemy.
It is always possible to make a new start by means of repentance. 'You fell,' it is written, 'now arise'(cf. Prov. 24:16). And if you fall again, then rise again, without despairing at all of your salvation, no matter what happens. So long as you do not surrender yourself willingly to the enemy, your patient endurance, combined with self-reproach, will suffice for your salvation. 'For at one time we ourselves went astray in our folly and disobedience,' says St. Paul. '... Yet He saved us, not because of any good things we had done, but in His mercy' (Tit. 3:3,5).
I am a Christian, you say, and content yourself with this. This is the first deceit - transferring to yourself the privileges and promise of Christianity, without any care to root true Christianity into yourself; or to ascribe to yourself that which can only be acquired by your strength and inner worthiness. Explain to yourself that it is illusory to hope in a name, that God can raise a son of Abraham from a stone and can take away your promise at any time if the conditions for participating in them are not soon fulfilled. Mainly, clarify to yourself what it means to be a Christian, unite yourself to this ideal, and you will see just how stable is this buttress to your blindness.
Set your sight on heaven and order every step of your life so that it will be a step in that direction. It seems to me that it is all so simple, and yet so all-embracing.
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.
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.
What do we do when attacked by some criminal? We strike out at him and shout for help. Our cries are answered by the police, who then rescue us from danger. We must do the same in inner warfare with the passions. Filled with anger against them, call for assistance: Help me, O Lord! Jesus Christ, Son of God, save me! O God, make speed to save me! O Lord make haste to help me! Having thus called on the Lord, do not allow your attention to wander from Him, do not let it turn to what is happening within you, but go on standing before the Lord and imploring His help. This will make the enemy run away as though pursued by flames.
