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.
Self-esteem is so deeply rooted in us and so firmly enmeshed in us, making us think that we are something, and something not unimportant, that it always hides in our heart as a subtle and imperceptible movement, even when we are sure that we do not trust ourselves and are, on the contrary, filled with complete trust in God alone. In order to avoid this conceit of the heart and act without any self-reliance, led only by your trust in God, take care always to preserve an attitude in which the consciousness and feeling of your weakness always precede in you the contemplation of God's omnipotence, and let both alike precede your every action.
The view we take of our Savior's dispensation is the view of the holy fathers who preceded us. By reading their works we equip our own mind to follow them and to introduce no innovation into Orthodoxy.
Fasting is beneficial when it is undertaken for quelling desire, humbling the soul, transforming hatred, extinguishing anger, erasing remembrance of wrongs, and for the purity of the understanding and the practice of prayer.
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.
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.
A life of fasting, properly understood as general self-limitation and abstinence, to the annual practice of which the Church always calls us with the Great Lent, is really that bearing of the cross and self-crucifixion which is required of us by our calling as Christians. And anyone who stubbornly resists this, wanting to live a carefree, happy, and free life, is concerned for sensual pleasures and avoids sorrow and suffering, that person is not a Christian. Bearing one's cross is the natural way of every true Christian, without which there is no Christianity.
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.
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.
Confirm yourself in this truth: that every Divine writing that is in agreement with the path of salvation instructs, teaches, chastises, and strengthens, that our path might be ever according to God.
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.
According to St. Gregory the Sinaite there are three degrees in eating: temperance, sufficiency, and satiety. Temperance is when someone wants to eat some more food but abstains, rising from the table still somewhat hungry. Sufficiency is when someone eats what is needed and sufficient for normal nourishment. Satiety is when someone eats more than enough and is more than satisfied. Now if you cannot keep the first two degrees and you proceed to the third, then, at least, do not become a glutton, remembering the words of the lord: 'Woe unto you that are full now, for you shall hunger' (Lk. 6:25). Remember also that rich man who ate in this present life sumptuously every day, but who was deprived of the desired bosom of Abraham in the next life, simply because of this sumptuous eating.