One should not ponder divine matters on a full stomach, say the ascetics. For the well-fed, even the most superficial secrets of the Trinity lie hidden.
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.
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.
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 belly when filled with all kinds of food gives birth to seeds of wantonness, nor can the mind, when choked with the weight of food, keep the guidance and government of the thoughts. For not only is drunkenness with wine wont to intoxicate the mind, but excess of all kinds of food makes it weak and uncertain, and robs it of all its power of pure and clear contemplation. The cause of the overthrow and wantonness of Sodom was not drunkenness through wine, but fullness of bread. Hear the Lord rebuking Jerusalem through the prophet. 'For how did thy sister Sodom sin, except in that she ate her bread in fullness and abundance?' (Ezek. xvi. 49)
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.
If you have promised Christ to go by the strait and narrow way, restrain your stomach, because by pleasing it and enlarging it, you break your contract. Attend and you will hear Him who says: 'Spacious and broad is the way of the belly that leads to the perdition of fornication, and many there are who go in by it; because narrow is the gate and strait is the way of fasting that leads to the life of purity, and few there be that find it.'
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.
No satiety has brought forth prudent behavior; for it is in the nature of fire to consume matter. And a filled stomach expels refined thoughts; it is the tendency of opposites to oppose each other.
It is not food that is evil but gluttony; not childbearing but fornication; not money but cupidity; not glory but vainglory. If this be so there is no evil in anything that is, except wrong use, which results from our mind neglecting to cultivate our nature (the powers of the soul, and their right direction).
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.
Fasting was of no benefit to that Pharisee in the Gospel, even though he always fasted two days a week, because he had adulterated it with pride and condemnation of his neighbor (Luke 18:11-12). Not that this means fasting is unprofitable. Moses, Elijah & the Lord Himself showed how beneficial it is for those who fast properly in a way pleasing to God.
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.
The hour of death will come upon us, it will come, and we shall not escape it. May the prince of this world and of the air (cf. John 14:30; Eph. 2:2) find our misdeeds few and petty when he comes, so that he will not have good grounds for convicting us. Otherwise we shall weep in vain. 'For that servant who knew his lord's will and did not do it as a servant, shall be beaten with many stripes' (cf. Luke 12:47).