On that day God will not judge us about psalmody, nor for the neglect of prayer, but because by abandoning them, we have opened our door to the demons.
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.
As soon as a man becomes humble, mercy is not slow to envelop him. Then the heart is aware of God’s help, and acquires a certain power of assurance (in God) which arises in it. And when a man is aware that God’s help is actually assisting him, his heart becomes filled with faith in very truth.
Ever let mercy outweigh all else in you. Let our compassion be a mirror where we may see in ourselves that likeness and that true image which belong to the Divine nature and Divine essence. A heart hard and unmerciful will never be pure.
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.
You know that evil entered into us through the transgression of the commandments. Hence it is obvious that by keeping them, evil departs from us. But without the doing of the commandments we should not even aspire or hope for purity of soul, because at the very outset we do not walk on the path that leads us to purity of soul. Do not say that God can give us the grace of purity of soul even without our keeping the commandments.
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.
If you love Christ God, then endure as He endured, and do all that is pleasing to Him. He taught and did. Unfailingly your love should be such as does good, endures, is disturbed by nothing present, and in everything ever thanks Him not with words and tongue, but with very deeds.