The moral character and moral value of man's personality depends most of all on the direction and strength of the will. Of course, everyone understands that for a Christian it is necessary to have first, a strong and decisive will, and second, a will which is firmly directed toward the good of his neighbor, toward the side of good and not evil. How is one to develop a strong will? The answer is simple: above all through the exercise of the will. To do this, as with bodily exercise, it is necessary to begin slowly, little by little. However, having begun to exercise one's will in anything ( e.g., in a constant struggle with one's sinful habits or whims) this work on oneself must never cease. Moreover, a Christian who wishes to strengthen his will, his character, must from the very beginning avoid all dissipation, disorder and inconsistency of behavior. Otherwise, he will be a person without character, unreliable, a reed shaking in the wind, as we read in Holy Scripture.
I shall speak first about control of the stomach, the opposite to gluttony, and about how to fast and what and how much to eat. I shall say nothing on my own account, but only what I have received from the Holy Fathers. They have not given us only a single rule for fasting or a single standard and measure for eating, because not everyone has the same strength; age, illness or delicacy of body create differences. But they have given us all a single goal: to avoid over-eating and the filling of our bellies... A clear rule for self-control handed down by the Fathers is this: stop eating while still hungry and do not continue until you are satisfied.
Let us be satisfied simply with what sustains our present life, not with what pampers it. Let us pray to God for this, as we have been taught, so that we may keep our souls unenslaved and absolutely free from domination by any of the visible things loved for the sake of the body. Let us show that we eat for the sake of living, and not be guilty of living for the sake of eating. The first is a sign of intelligence, the second proof of its absence.
No one can be saved without the renunciation of his will, even though he might struggle fervently, for our will and our manner are like a bronze wall between us and God.
An elder prescribes the following rule of conduct for the monastic table: 'When you sit to eat, brother, do not be overcome by the demon of gluttony, which compels you to eat in a disorderly way and in haste and to desire to taste many kinds of food together. Learn to eat modestly and in an orderly way and maintain a measure of restraint.'
There is a difference, Dearly Beloved Brethren, between the delights of the body and those of the soul, that the delights of the body, when we do not possess them, awaken in us a great desire for them; but when we possess them and enjoy them to the full they straightway awaken in us a feeling of aversion. But spiritual delights work in the opposite way. While we do not possess them we regard them with dislike and aversion; but once we partake of them we begin to desire them, and the more do we hunger for them. In one case the appetite pleases, the reality brings displeasure; in the other it is the appetite [that] displeases, the reality delights us more and more. In the one case appetite leads to fullness, and fullness to disgust; in the other appetite begets fullness, and fullness in turn begets appetite. For spiritual delights, when they fill the soul, increase in us a desire of them; and the more we savor them, the more do we come to know what we should eagerly love.
If we want to do something but cannot, then before God, Who knows our hearts, it is as if we have done it. This is true whether the intended action is good or bad.
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.
In everything we do, God looks as the aim, whether it is for Him or for some other purpose we act. So, when we wish to do something good, let us have as our aim not to please men but to please God, so as to have our eyes always fixed on Him, doing everything for Him, lest we bear the labor but lose the reward.