Fasting is absolutely indispensable for man. From the external aspect, it is a struggle of filial obedience to God, Who has given us the rules of fasting through His Holy Spirit. From the inner aspect, fasting is a struggle of restraint and self-limitation. In this lies the great value and sense of fasting, since a strict observance of fasts tempers one's will and perfects the character of one who is firm in his religious convictions and actions. Let us not forget that Christ Himself fasted, and foretold that His apostles would also fast.
The partaking of food has three degrees: abstinence, adequacy and satiety. To abstain, means to remain a little hungry after eating; to eat adequately, means neither to be hungry, nor weighed down. But eating beyond satiety is the door to belly-madness, through which lust comes in. But you, firm in knowledge, choose what is best for you, according to your powers, without overstepping the limits...
The reason that fasting has an effect on the spirits of evil rests in its powerful effect on our own spirit. A body subdued by fasting brings the human spirit freedom, strength, sobriety, purity, and keen discernment.
No matter what misfortune might befall you, no matter what unpleasantness might occur, say 'I will endure this for Jesus Christ's sake!' Just say that, and you will feel better, for the Name of Jesus Christ is powerful. Before It, all difficulties abate, and demons disappear. Your annoyance and faintness of heart will abate when you repeat His most sweet Name. Lord, grant unto me to see my transgressions. Lord, grant unto me patience, magnanimity, and meekness.
If a king wanted to take possession of his enemy's city, he would begin by cutting off the water and the food and so his enemies, dying of hunger, would submit to him. It is the same with the passions of the flesh; if a man goes about fasting and hungry the enemies of his soul grow weak.
Let those of us who have wisely finished the course of fasting and who celebrate with love the beginning of the suffering of the Passion of the Lord, let us all, my brothers, zealously imitate the purity of self-controlled Joseph; let us fear the sterility of the fig tree; let us dry up through almsgiving the sweetness of passion. In order that we may joyously anticipate the Resurrection, let us procure like myrrh pardon from on high, because the eye that never sleeps observes all things.
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.
What good is it to keep meat out of your mouth if you bite your brother with wickedness? What good does it serve you to observe a strict frugality at home if you unjustly steal from the poor? What kind of piety teaches you to drink water while you hatch plots and drink the blood of a man you have shamefully cheated? Judas, after all, fasted along with the eleven, but failed to master his greed; his salvation gained nothing by fasting. And the devil does not eat, for he is an incorporeal spirit, but he fell from on high through wickedness. Likewise, none of the demons can be accused of gorging themselves, of excessive drinking or getting drunk, for their nature makes feeding unnecessary; nevertheless, night and day, they roam through the air, agents and servants of evil, eager for our loss. They ooze with bitterness and jealousy—things it is well to avoid—at the idea that humans may enter into an intimacy with God, since they have fallen from the supremely worthy dwelling.
Fasting is acceptable to God when abstention from food is accompanied by refraining from sins, from envy, from hatred, from calumny, from vainglory, from wordiness, from other evils. He who is fasting the true fast `that is agreeable' to God ought to shun all these things with all his strength and zeal, and remain impregnable and unshakeable against all the attacks of the evil one that are planned from that quarter. On the other hand, he who practices abstention from food, but does not keep self-control in the face of the aforesaid passions, is like unto one who lays down splendid foundations for a house, yet takes serpents and scorpions and vipers as fellow-dwellers therein.
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.
The man who does not humble himself and does not cleanse his heart from evil desires fasts in vain. He may eat nothing at all, but it will be to no avail if there is evil inside him. He must first cleanse himself from the evil within in order to receive the Lord.
We must not only keep a sharp watch over our diet, but keep away from all other kinds of sin so that as our stomach keeps fast, so also may our tongue as we abstain from calumny, from deceit, from idle talk, from railing and anger and all other vices which arise from the tongue. So also let our eyes keep fast. No looking for trivialities, no letting the eyes wander freely, no impudent lying in wait for people to talk to. The same with the hands and feet, to prevent them from doing anything evil. Fasting in this way, as St. Basil says, is an acceptable fast and, leaving behind all the evil to which our senses are inclined, we may come to the holy day of Resurrection, renewed and clean and worthy to share in the Holy Mysteries.
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.
Many abstain from meat, milk and other food which God has not forbidden and which was even given as a blessing of people who have learned the truth and know how to partake of these things with thanksgiving (I Tim. 4:34). But the same abstemious, devout-living people, give scandal by their action, and spread scandal with their tongue like an incendiary fire.
The right practice of abstinence is needful not only to the mortification of the flesh but also to the purification of the mind. For the mind then only keeps holy and spiritual fast when it rejects the food of error and the poison of falsehood.
Hold faith and humility fast within you; for through them you will find mercy, help, and words spoken by God in the heart, along with a protector who stands beside you both secretly and manifestly.
The Holy Fathers recommend 'moderate' fasting; one ought not to allow the body to be weakened too much, for then the soul, too, is harmed. Nor ought one to undertake fasting too suddenly; everything demands practice, and each one should look to his own nature and occupation. To choose among different kinds of food is to be condemned; all food is God-given, but it is advisable to avoid such kinds as add to the body's weight and appetite; strong spices, meat, spirituous drinks and such foods as are solely for the palate's enjoyment. For the rest, one may eat what is cheap and most easily available, they say. But by 'moderate' they mean one meal a day, and that one light enough not to fill the stomach to satiety.