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.
For as merchants on a voyage, though they find a wind to suit them and the sea calm, but have not yet reached the haven, are always subject to fear, lest suddenly a contrary wind should stir and the sea rise into billows, and the ship be in peril, so Christians, even if they have in themselves a favorable wind of the Holy Spirit blowing, are nevertheless yet subject to fear, lest the wind of the adverse power should rise and blow on them, and stir disturbance and billows for their souls. There is need therefore of great diligence, that we may arrive at the haven of rest, at the perfect world, at the eternal life and pleasure, at the city of the saints, at the heavenly Jerusalem, at the church of the firstborn (Heb. xii. 23.). Unless a man gets through these measures, he is under much fear, lest in the meantime the evil power should effect some fall.
Patience adorns the soul with diamonds which are not of the earth but belong to the Jerusalem that is above. Patience is a sweet word. Patience is a sweet breath. Patience is an invincible weapon. Patience is a priceless adornment of man. Patience is a blessing of God.
When a man has been sufficiently illumined, however, to perceive his own faults, he never ceases mourning for himself and for all men, seeing God’s great forbearance and what sins we in our wretchedness have committed and still persist in committing. As a result of this he becomes full of gratitude, not daring to condemn anyone, shamed by the profusion of God’s blessings and the multitude of our sins. Thereupon he joyfully renounces everything in his own will that is counter to God, and he watches over his own senses, so as to prevent them from doing anything beyond what is unavoidably needed.
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.
They asked Abba Macarius, 'How should we pray?' And the old man replied, 'There is no need to speak much in prayer; often stretch out your hands and say, 'Lord, as you will and as you know, have mercy on me.' But if there is war in your soul, add, 'Help me!' and because he knows what we need, he shows mercy on us.'
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.
What can God do with one who willfully gives himself over to the world, and is deceived by its pleasures, or led astray by material wanderings? The man to whom He gives help is the one who turns away from material pleasures and from his former habits, who drags his mind at all times to the Lord, whether it will or not, who denies himself and seeks the Lord only. This is the man whom He keeps under His care: who guards himself on every side from the snares and entanglements of the material world, who works out his own salvation with fear and trembling, who passes with all heed amidst the snares and entanglements and lusts of this world, and seeks the help of the Lord, and hopes by His mercy to be saved through grace.
Such are the souls of the saints: they love their enemies more than themselves, and in this age and in the age to come they put their neighbor first in all things, even though because of his ill-will he may be their enemy.
One of the Fathers said: just as it is impossible for a man to see his face in troubled water, so too the soul, unless it be cleansed of alien thoughts, cannot pray to God in contemplation.
The most important thing in any good effort and the height of all activities is to persevere in prayer, by means of which we can always acquire through supplication the other virtues from God as well.
Keep both eyes open. This is the measure of humility: if a man is humble he never thinks that he has been treated worse than he deserves. He stands so low in his own estimation that no one, however hard they try, can think more poorly of him than he thinks of himself.
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.