Observe your thoughts, and beware of what you have in your heart and your spirit, knowing that the demons put ideas into you so as to corrupt your soul by making it think of that which is not right, in order to turn your spirit from the consideration of your sins and of God.
Fasting needn't be limited to abstinence from food alone, because true fasting is departure from evil deeds. Forgive your neighbor any insult, abstain from causing your neighbor offence, abstain from irritation, from senseless sorrows, from fear, wrath, and so on. ‘True fasting is alienation from evil, temperance of the tongue, setting aside of wrath, casting out of lust, idle talk, lies, and oath-breaking’…This is a true and pleasing fast for the Lord. Departing from these vices and from a corrupt state is what comprises a true fast.
Truth is the foundation of everything that has been created. Let truth be also the foundation of all your works (both inward and outward), and especially the foundation of your prayers. Let all your life, all your works, all your thoughts, and all your desires be founded upon truth.
'Behold, Satan hath desired to have you, that he may sift you as wheat' (Lk. 22:31). It is he who so greatly distracts our thoughts in the temple during Divine Service and at home during prayer; it is he who draws away your thoughts from God, from our souls and the souls of others, from heavenly and eternal things; it is he who occupies us with early trifles or with earthly vanity, with earthly nothingness, with earthly allurements, with food, drink, dress, houses, etc. We must pray for each other that our faith should not fail as the Savior prayed for Peter.
The images of worldly vanity, upon which we have looked with entire pleasure and hearty sympathy, effeminate, weaken, and disturb the soul; they deprive us of purity of heart and of boldness before God.
When praying, endeavor by every means to feel in your heart the truth and the power of the words of the prayer; feed yourself upon them as upon an imperishable food; water your heart with them as with a dew; and warm yourself by them as by means of a beneficial fire.
Our soul is simple as thought, and rapid as thought or lightning. In an instant it can be wounded by sin and become attached to corruptible things; in an instant it can fall away from the love of God and its neighbor through a single unrighteous thought, through a single passionate desire, through a single malevolent thought, and, therefore, we must constantly watch our heart, lest it should incline to words or thoughts of evil, and must ever strive to preserve it in God's simplicity and purity, and in the love of God and its neighbor.
In order not to be in daily bondage to the passions and the devil, you must set yourself an object to aim at, have this object constantly in view, and endeavor to attain it, conquering all obstacles by the name of the Lord. What is this object? The Kingdom of God, the Divine palace of glory, prepared for believers from the creation of the world. But as this object can only be attained by certain means, it also is necessary to have such means at one's disposal. And what are these means? Faith, hope, and love, especially the last. Believe, hope, and love, especially love, disregarding all obstacles; love God above everything and your neighbor as yourself. If you have not sufficient strength to preserve in your heart these inestimable treasures, fall down more often at the feet of the God of Love. Ask, and it shall be given you; seek and ye shall find; knock and it shall be opened unto you, for He Who has promised is true. Walking, sitting, lying down, conversing, or working, at every time, pray with your whole heart that faith and love may be given to you. You have not yet asked for them as you should ask - fervently and instantly - with the firm purpose of obtaining them. Say now, 'I will begin to do so henceforth.'
When the flesh flourishes, the soul fades; when the flesh has full liberty, the soul is straitened; when the flesh is satiated, the soul hungers; when the flesh is adorned, the soul is deformed; when the flesh overflows with laughter, the soul is surrounded by misfortune; when the flesh is in the light, the soul is in darkness...
Reverence with all the powers of your soul all the sacraments, and say to yourself in respect to every sacrament before the celebration or the communion of it: `This is God's mystery. I myself am only the unworthy witness or partaker of it.' Otherwise our proud intellect even wishes to search out God's mystery, and, if unable to penetrate it, rejects it as not coming under the small measure of our intellect.
Keep a strict watch against any appearance of pride: it appears imperceptibly, particularly in time of vexation and irritability against others for quite unimportant causes.
As water standing behind an earth dam, and finding an aperture, washes it wider and wider and filters through it, if we do not strengthen the dam, or strengthen it insufficiently, at last, with growing weakness on our part and with repeated efforts, the water gets through with greater and greater force, so that at last it becomes very difficult, and even impossible to stop it; so also with malice hidden in the heart of man: if we let it pierce through once, twice, and thrice, it will pour out more and more powerfully, & may at last break through and overflow your dam.
If you do not experience in yourself the influence of the evil spirit, you will not know and you will not value as you should the goodness shown to you by the benevolence of the Holy Spirit; not having known the spirit that destroys, you also will not know the Life-giving Spirit. Only because of contrary opposites of good and evil, of life and death, we understand one and the other... 'Glory to God, the Wise and All-Good, that He permits the spirit of evil and death to tempt us and cause us suffering. Otherwise, how could we begin to value the consolation of Grace, the consolation of the Holy Spirit, the Comforter and Life-giver!'