Fasting, while of value in itself, is not something to boast of in front of God, for it is simply a tool for training those who desire self-restraint. The ascetic should not feel proud because he fasts; no artist ever boasts that his accomplishment is simply due to his tools; but he waits for the work itself to give proof of his skill.
Suppose you have ordered yourself not to eat fish; you will find that the enemy continually makes you long to eat it. You are filled with an uncontrollable desire for the thing that is forbidden. In this way you can see how Adam's fall typifies what happens to all of us. Because he was told not to eat from a particular tree, he felt irresistibly attracted to the one thing that was forbidden him.
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.
Be slow and dull to idle talk, but knowing and wise in hearkening to the saving words of the Holy Scriptures. Let the hearing of worldly tales be to you as a bitter taste in your mouth, but the discourse of holy men as a honeycomb (Prov. 16.24). Be eager to imitate men of disciplined habits and do not wait to be taught each thing. Strive to attain to the greater virtues, but do not neglect the lesser ones. Do not make light of a fall even if it be the most venial of faults; rather, be quick to repair it by repentance, although many others may commit a large number of faults, slight and grievous, and remain unrepentant. Judge not the sins of others, for they have a just Judge ‘Who will render every man according to his works’ (Rom. 2.6); but be master of what is your own and lighten your own burden insofar as you have the power, for he who increases his own burden will also carry it. In repentance is salvation, but folly is the death of repentance.
It is impossible for the soul to be liberated from turbulent thoughts without the virtue of non-possessiveness. And without peace of the bodily senses it is impossible for the soul to have a peaceful intellect. And if it does not come into temptations it will not acquire wisdom of the Holy Spirit. And without laborious and persistence in reading, it will not come to the discernment of thoughts. And without the stillness of thoughts, the intellect cannot move to seek the hidden mysteries of God.
When you fast and are nourished with abstinence, do not store the leftovers for tomorrow, but, as the Lord became poor and enriched us, feed someone who does not want to be hungry, you who hungers willingly. Then your fast will be like the dove who brings and joyfully proclaims salvation to your soul from the flood.
In this time of fasting and prayer, brethren, let us with all our hearts forgive anything real or imaginary we have against anyone. May we all devote ourselves to love, and let us consider one another as an incentive to love and good works, speaking in defense of one another, having good thoughts and dispositions within us before God and men. In this way our fasting will be laudable and blameless, and our requests to God while we fast will be readily received.
And finally, did not the Lord Jesus Himself begin His divine ministry of the salvation of mankind with a long, forty day fast? And did not He, in this way, clearly show that we must make a serious beginning to our life as Christians with fasting? First, the fast, and then all the rest comes together with, and through, the fast. By His own example, the Lord showed us how great a weapon fasting is. With this weapon, He vanquished Satan in the wilderness, and with it was victorious over the three chief satanic passions with which Satan tempted Him: love of ease love of praise and love of money. These are three destructive greeds, the three greatest traps into which the evil enemy of the human race lures Christ's soldiers.
If a person swallows too much food, he is inviting impure thoughts. If he mortifies the stomach, he is creating pure thoughts. Often a lion if it is caressed becomes domesticated, whereas the more you coddle the body, the more it goes wild.
Do not oppose the thoughts, which the enemy sows in you, but rather cut off all converse with them by prayer to God. We have not always strength enough so to oppose hostile thoughts as to stop them; on the contrary, in such attempts they frequently inflict us with a wound that is long in healing.
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.
All the pleasers of God are like the angels in their love and devotion. They, just as the angels, waged war against the dark forces, and became strengthened in love of God. All of the prophets of the Old Testament lived in such a struggle. Godlessness prevailed, the Law of God was forgotten. The world persecuted them because they interfered with its sinful life. They hid in the 'depths of the earth.' The world hated them. The prophet Isaiah was sawed in two by a wooden saw, the prophet Jeremiah was trampled in a swamp. And in such surroundings they stood fast in faith and devotion. All righteous ones were sorrowful in the world because they were strangers to the sinful world. All of the apostles suffered in one way or another. Righteous men left for the desert. What made them saints? Suffering? Not suffering alone makes saints, but striving towards God, love of God, and the labor of overcoming obstacles to holiness, which is the fruit of man's labor and the gift of the Holy Spirit.
I shall speak first about control of the stomach, the opposite to gluttony, and about how to fast and what and how much to eat. I shall say nothing on my own account, but only what I have received from the Holy Fathers. They have not given us only a single rule for fasting or a single standard and measure for eating, because not everyone has the same strength; age, illness or delicacy of body create differences. But they have given us all a single goal: to avoid over-eating and the filling of our bellies... A clear rule for self-control handed down by the Fathers is this: stop eating while still hungry and do not continue until you are satisfied.
Beware of limiting the good of fasting to mere abstinence from meats. Real fasting is alienation from evil. ‘Loose the bands of wickedness.’ For give your neighbor the mischief he has done you. Forgive him his trespasses against you. Do not ‘fast for strife and debate.’ You do not devour flesh, but you devour your brother. You abstain from wine, but you indulge in outrages. You wait for evening before you take food, but you spend the day in the law courts. Woe to those who are ‘drunken, but not with wine.’ Anger is the intoxication of the soul, and makes it out of its wits like wine.
Fasting is the champion of every virtue, the beginning of the struggle, the crown of the abstinent, the beauty of virginity and sanctity, the resplendence of chastity, the commencement of the path of Christianity, the mother of prayer, the well-spring of sobriety and prudence, the teacher of stillness, and the precursor of all good works. Just as the enjoyment of light is coupled with healthy eyes, so desire for prayer accompanies fasting that is practiced with discernment.