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 spiritual discipline of fasting is a tool for shifting the focus away from us and toward the Lord and our brothers and sisters in whom we encounter Him each day. If we distort fasting into a private religious accomplishment to prove how holy we are, we would do better not to fast at all. That would simply be a way of serving ourselves instead of God and those who bear His image and likeness. In Lent, our focus must be set squarely on Christ and His living icons, not on us. The fundamental calling of the Christian life is to become like our Lord, Who offered Himself up for the salvation of the world purely out of love. If we are truly in communion with Him, then we too must offer up ourselves for our neighbors. And as He taught in the parable of the Good Samaritan, there are no limits on what it means to be a neighbor to anyone who is in need, regardless of nationality, culture, or anything else. Those who limit their concern for people according to such standards place serving the kingdoms of this world before fidelity to the Kingdom of God.
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.
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.
Concerning fasting, do not grieve, as I have said to you before: God does not demand of anyone labors beyond his strength. And indeed, what is fasting if not a punishment of the body in order to humble a healthy body and make it infirm for passions, according to the word of the Apostle: 'When I am weak, then am I strong' (II Corinthians 12:10).
To what end do fasting and penitence lead? For what purpose is this trouble taken? They lead to the cleansing of the soul from sins, to peace of heart, to union with God; they fill us with devotion and sonship, and give us boldness before 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.
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.
In no art do the artists judge the result of their work by the tools they use, but they await the work's completion and by it judge the art. Adopting such a practice with regard to food, not placing all your hope on fasting, but fasting moderately and according to the amount of your strength, strive toward mental activity. In this way you can avoid pride and will not spurn God's good works, sending up praises to God for everything.
It is necessary most of all for one who is fasting to curb anger, to accustom himself to meekness and condescension, to have a contrite heart, to repulse impure thoughts and desires, to examine his conscience, to put his mind to the test and to verify what good has been done by us in this or any other week, and which deficiency we have corrected in ourselves in the present week. This is true fasting.
Almsgiving heals the soul's incensive power; fasting withers sensual desire; prayer purifies the intellect and prepares it for contemplation of created beings. For the Lord has given us commandments which correspond to the powers of the soul.
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.
Bodily purity is primarily attained through fasting, and through bodily purity comes spiritual purity. Abstinence from food, according to the words of that son of grace, St. Ephraim the Syrian, means: 'Not to desire or demand much food, either sweet or costly; to eat nothing outside the stated times; not to give oneself over to gratification of the appetite; not to stir up hunger in oneself by looking at good food; and not to desire one or another sort of food.
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.
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.