To wage war only with the sins that make their appearance as actual deeds would be just as unsuccessful as cutting down weeds in a garden instead of digging them up at the root and throwing them out. Sins appear as inevitable outgrowths from their roots, the passions of the soul.
When despondency seizes us, let us not give in to it. Rather, fortified and protected by the light of faith, let us with great courage say to the spirit of evil: 'What are you to us, you who are cut off from God, a fugitive for Heaven, and a slave of evil? You dare not do anything to us: Christ, the Son of God, has dominion over us and over all. Leave us, you thing of bane. We are made steadfast by the uprightness of His Cross. Serpent, we trample on your head.'
Do not judge one another, for you transgress the evangelical law, and 'every transgression and disobedience received a just retribution' (Heb. 2:2). 'Who are you to pass judgment on the servant of another?' (Rom. 14:4). Do you not know that the one who passes judgment goes astray through pride, and that everyone who exalts himself will be humbled (Luke 14:11) by the Lord, when temptation seizes him?
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.
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.
We have become so inattentive to the work of our salvation that we misinterpret many other words in Holy Scripture as well, all because we do not seek the grace of God and in the pride of our minds do not allow it to dwell in our souls. That is why we are without true enlightenment from the Lord, which He sends into the hearts of men who hunger and thirst wholeheartedly for God’s righteousness or holiness.
If we desire to acquire faith the foundation of all blessings, the door to God's mysteries, unflagging defeat of our enemies, the most necessary of all the virtues, the wings of prayer and the dwelling of God within the soul--we must endure every trial imposed by our enemies and by our many and various thoughts... if we forcibly triumph over the trials and temptations that befall us, it will not be we who are victorious, but Christ, Who is present in us through faith.
'Lord Jesus Christ, Son of God, have mercy on me, a sinner.' Let your attention and instruction be centered on this. Walking, eating, standing in church before the beginning of the service, continue with the prayer; on entering and departing keep this prayer on your lips and within your heart. In such a manner, with the invocation of the Name of God you will find peace, you will attain to purity of spirit and body; and the Holy Spirit, the Origin of all good, will make for Himself a dwelling within you and will guide you in all piety and purity.
Courage does not consist in defeating and oppressing one's neighbor, for this is overbearingness, which oversteps the bounds of courage. Nor again does it consist in fleeing terrified from the trials that come as a result of practicing the virtues; for this is cowardice and falls short of courage. Courage itself consists in persisting in every good work and in overcoming the passions of soul and body. For our struggle is not against flesh and blood, that is, against men, as was the case with the Jews of old, where to conquer other nations was to do the work of God; it is against principalities and powers, that is, against the unseen demons (Ephesians 6:12). He who is victorious conquers spiritually; otherwise he is conquered by the passions. The warfare described in the Old Testament prefigures our spiritual warfare. These two passions of overbearingness and cowardice, though they appear to be opposites, are both caused by weakness. Overbearingness pulls one upwards and is outwardly something startling and frightening, like some powerless bear, while cowardice flees like a chased dog. No one who suffers from either of these two passions puts his trust in the Lord, and therefore he cannot stand firm in battle, whether he is overbearing or cowardly. But the righteous man is as bold as a lion (Proverbs 28:1) in Christ Jesus our Lord, to whom be glory and dominion throughout the ages.
One must endeavor to read through the writings of the Fathers, and strive as much as possible, according to one’s strength, to fulfill what they teach, and in this fashion, little by little ascend from the ascetic life to the perfection of the contemplative.
The body is a slave, the soul a sovereign, and therefore it is due to Divine mercy when the body is worn out by illness: for thereby the passions are weakened, and a man comes to himself; indeed, bodily illness itself is sometimes caused by the passions.
Fasting is an exceptional virtue; it represses bodily impulses and gives strength to the soul to fight against the poisoning of the heart through the senses, and provides it with a remedy against any past poisoning. Fasting causes the mind to be cleansed constantly. It withers up every evil thought and brings healthy, godly thoughts -- -holy thoughts that enlighten the mind and kindle it with more zeal and spiritual fervor.