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.
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.
Truly wretched and three times miserable is the soul that has left the world and dedicated itself to God but has not lived in a manner worthy of its promise. Then, brothers, let us not allow this age, which is short and contemptible and passes like a shadow, to steal that blessed and immortal life away from us.
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.
He who wishes to tear up the account of his sins and to be inscribed in the Divine book of the saved, can find for this purpose no better means than obedience.
The origin of the Christian life is in arousal by grace. A person who has heeded this arousal is not then deprived of guidance by grace and communion with it at all times, as it persists through proper attention to it.
The zealous are eager for ascetical struggles of self-forcing and self-opposition with the aim of self-correction, or of raising themselves to primordial purity, so that they might all the more speedily become worthy of communion with God. Obviously the more eager one is, the more diligently and longingly he does this, the sooner he achieves his goal.
From this minute of his new life, the repentant sinner commences his podvig, struggle, and labor, and begins to bear the burden, the yoke. This is so essential that all the saints accept the only true path to virtue to be pain and hard work. On the contrary, lightness and ease are a sign of a false path, for the kingdom of God suffereth violence, and the violent take it by force (Matt. 11:12). Anyone who is not struggling, not in podvig, is in prelest.
You have the book of discourses by St. Macarius of Egypt. Kindly read the 19th discourse, concerning a Christian's duty to force himself to do good. There it is written, 'One must force oneself to pray, even if one has no spiritual prayer.' And, 'In such a case, God, seeing that a man earnestly is striving, pushing himself against the will of his heart (that is, his thoughts), He grants him true prayer.' By true prayer, St. Macarius means the undistracted, collected, deep prayer that occurs when the mind stands unswervingly before God. As the mind begins to stand firmly before God, it discovers such sweetness, that it wishes to remain in true prayer forever, desiring nothing more.
Even if a person’s sin is not only obvious, but very grievous and comes from a hardened and unrepentant heart, do not condemn him, but raise your eyes to the wondrous and incomprehensible judgments of God; then you will see that many people, formerly full of iniquity, later repented and reached a high degree of sanctity, and that, on the other hand, others, who were on a high level of perfection, fell into a deep abyss. Take care, lest you also suffer this calamity through judging others.
Our prayer reflects our attitude towards God. He who is careless of salvation has a different attitude toward God from him who has abandoned sin and is zealous for virtue but has not yet entered within himself and works for the Lord only outwardly. Finally, he who has entered within and carries the Lord within himself, standing before Him, has yet another attitude. The first man is negligent in prayer, just as he is negligent in life, and he prays in church and at home merely according to the established custom, without attention or feeling. The second man reads many prayers and goes often to church, trying at the same time to keep his attention from wandering and to experience feelings in accordance with the prayers which are read, although he is seldom successful. The third man, wholly concentrated within, stands with his mind before God, and prays to Him in his heart without distraction, without long verbal prayers, even when standing for a long time at prayer in his home or in church.... Every prayer must come from the heart and any other prayer is no prayer at all. Prayer-book prayers, your own prayers and very short prayers, all must issue forth from the heart to God, seen before you.
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.
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.
Faith is the sincere confession that God, Who is worshipped in the Trinity, Who created all things and provides for all, saves us who are fallen, through the power of the death on the Cross of the incarnate Son of God, by the grace of the Most Holy Spirit in His Holy Church. The beginnings of renewal, which are established in this life, will appear in all their glory in the future age, in a way that the mind cannot comprehend nor the tongue express.
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.