Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
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.
When walking in the way of righteousness, it is impossible not to meet with trouble, or that the body should not suffer pain and weakness and should remain immutable, if we want to live in virtue.
We must accomplish the course of our earthly pilgrimage with the greatest attention and watchfulness over ourselves, unceasingly calling upon God in prayer for help.
A sorrowless earthly life is a true sign that the Lord has turned his face from a man, and that he is displeasing to God, even though outwardly he may seem reverent and virtuous.
Having guarded ourselves against distractions and worries, let us turn our attention to our body on which mental vigilance is completely dependent. Human bodies differ widely from one another in strength and health. Some by their strength are like copper and iron; others are frail like grass. For this reason everyone should rule his body with great prudence, after exploring his physical powers. For a strong and healthy body, special fasts and vigils are suitable; they make it lighter, and give the mind a special wakefulness. A weak body should be strengthened by food and sleep according to one's physical needs, but on no account to satiety. Satiety is extremely harmful even for a weak body; it weakens it, and makes it susceptible to disease. Wise temperance of the stomach is a door to all the virtues. Restrain the stomach, and you will enter Paradise. But if you please and pamper your stomach, you will hurl yourself over the precipice of bodily impurity, into the fire of wrath and fury, you will coarsen and darken your mind, and in this way you will ruin your powers of attention and self-control, your sobriety and vigilance…
Some fast, live as solitaries without possessions, and pray that God will curb their nature; yet in spite of this, they allow themselves to slander, to reproach and judge their neighbors and ridicule them - and so the Divine help departs from them. They are left to themselves and are unable to find strength needed to counteract our nature's sinful suggestions. In a certain cenobitic monastery, there lived a hermit whose name was Timothy. One of the brethren in the cenobium became subject to temptation. When the abbot heard about this, he asked Timothy how the fallen brother should be treated. The hermit advised him that the seduced one should be expelled. And when they had sent him away, the fallen brother's temptation fell upon Timothy, so that he was in peril. Timothy began tearfully to groan for help and mercy from God. A voice came to him, 'Timothy, know that I have sent this temptation to you, because you disdained your brother in his hour of temptation.' One must deal with the members of Christ - Christians - with great care and circumspection. One must actually suffer with them in their weakness, cutting off only those who show no hope for restored health, lest they infect others with their ailments.
According to the teachings of the Holy Fathers, in order to destroy insensibility man needs a constant, patient, uninterrupted activity against insensibility; he needs a constant, pious, and attentive life.
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.