Abba Poemen used to say, “Satan has three kinds of power which precede all sin. The first is error, the second is neglect (or laxity), and the third is lust. When error has come it produces neglect, and from neglect springs lust, and by lust man fell; if we watch against error neglect will not come, and if we be not negligent, lust will not appear, and if a man works not lust, he will, through the help of Christ, never fall.
Abba Lot went to see Abba Joseph and said to him, ‘Abba as far as I can I say my little office, I fast a little, I pray and meditate, I live in peace and as far as I can, I purify my thoughts. What else can I do?’ then the old man stood up and stretched his hands towards heaven. His fingers became like ten lamps of fire and he said to him, ‘If you will, you can become all flame.’
Do you want to know how much fasting adorns human beings; how much she defends and secures us from danger? I beg of you, think of the blessed and marvelous race of the monastics. In other words, they took flight from the tumult in their midst and they ran quickly to the peaks of the mountains; they erected their huts in the solitude of the desert as if they pitched them in a sheltered harbour; and they took fasting as a companion and joint communicant throughout their entire lives. This is why she made them angels from men; not only them, but as many as she finds in the cities that submit to her, she elevates to the same height of the wisdom of God.
Likewise Moses and Elijah, the pillars of the prophets in the Old Testament – although they were brilliant and great from their other virtues and courageous in approaching God and conversing with Him, as much as is humanly possible – fled for refuge to fasting, and with her power they approached Him.
For this reason, God, when in the beginning he created man, He immediately brought him over to and deposited him in the hands of fasting; and he entrusted his salvation to her as if to a loving mother and an excellent teacher. Because the command: “Of every tree which is in the garden you may freely eat, but of the tree of knowledge of good and evil, of it you shall not eat” (Gen 2.16) was one kind of fasting. If fasting was imperative in paradise, much more so was it outside of paradise. If the medicine was useful before the wound, much more so was it after the wound. If the weapon was necessary for us before the rising of the war of the passions and the tremendous battle with the demons, much more so will the defense of fasting be indispensable. If Adam had heard the voice (Gen 2.16), he would not have heard the second one, which said: “You are earth, and to earth you shall return” (Gen 3.20). However since he disobeyed that voice, death, anxieties, toils, faintheartedness, and a life that is altogether more burdensome than death came upon the human race; this is why thorns and thistles came about, this is the reason for the labours and pains and a life weary with toil.
[St. John Chrysostom, On Fasting and the Prophet Jonah, [the Prophet] Daniel and the Three Youths]
On one occasion some early grapes were sent to Abba Macarius because he longed for them, and to give a proof of his abstinence, he sent them to another brother who was sick, and who craved for grapes; and having received them, he rejoiced over them greatly, and then he despised his desire, and sent them on to another brother, as one who had no wish for food of any kind, and who held his self-denial in contempt. Now when the brother had received the grapes, although he desired greatly to eat them, he did the same as the other brother had done, and no man wished to eat them. And after they had gone about among many brethren, the last one who received them sent them to the blessed Macarius as a gift of great honour; and when the blessed Macarius saw the grapes he marvelled at the extent of the self-denial of the brethren, and gave thanks unto God, and he did not eat them.
“He did not deal with us according to our sins, Nor reward us according to our transgressions; For according to the height of heaven from earth, So the Lord reigns in mercy over those who fear Him.” (Psalm 102:10-11)
Thanks unto God, because He has granted this. We have not received what we were deserving of: “He did not dealt with us according to our sins, nor reward us according to our transgressions. For according to the height of heaven from earth, So the Lord reigns on mercy over those who fear Him.”
Observe the heaven: everywhere on every side it covers the earth, nor is there any part of the earth not covered by the heaven. Men sin beneath heaven: they do all evil deeds beneath the heaven; yet they are covered by the heaven. From it is light for the eyes, from it air, from it breath, from it rain upon the earth for the sake of its fruits, from heaven all mercy. Take away the aid of heaven from the earth: it will fail at once. As then the protection of heaven abides upon the earth, so does the Lord’s protection abide upon them that fear Him. You fear God, His protection is above you.
But perhaps you are scourged, and think that God has forsaken you. God has forsaken you if the protection of heaven has forsaken the earth.
[Augustine of Hippo, Exposition on the Psalms, Psalm CIII]