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.
Even if you have only bread or water, with these you can still meet the dues of hospitality. Even if you do not have these, but simply make the stranger welcome and offer him a word of encouragement, you will not be failing in hospitality. Think of the widow mentioned in the Gospel by our Lord: with two mites she surpassed the generous gifts of the wealthy.
The Holy Fathers recommend 'moderate' fasting; one ought not to allow the body to be weakened too much, for then the soul, too, is harmed. Nor ought one to undertake fasting too suddenly; everything demands practice, and each one should look to his own nature and occupation. To choose among different kinds of food is to be condemned; all food is God-given, but it is advisable to avoid such kinds as add to the body's weight and appetite; strong spices, meat, spirituous drinks and such foods as are solely for the palate's enjoyment. For the rest, one may eat what is cheap and most easily available, they say. But by 'moderate' they mean one meal a day, and that one light enough not to fill the stomach to satiety.
To the world belong our desires and impulses. enumerates them: Weakness for wealth and for collecting and owning things of different kinds; the urge for physical (sensuous) enjoyment; the longing for honor, which is the root of envy; the desire to conquer and be the deciding factor; pride in the glory of power; the urge to adorn oneself and to be liked; the craving for praise; concern and anxiety for physical well-being. All these are of the world; they combine deceitfully to hold us in heavy bonds. If you wish to free yourself, scrutinize yourself with the help of that list and see clearly what you have to struggle against in order to approach God. For friendship with the world is enmity with God, and whosoever therefore will be a friend of the world is the enemy of God (James 4:4).
One must train oneself in generous patience, so as to endure without complaint all that happens to us. We will possess patience when we accept everything that happens to us, both what is joyful and what is sad, without distinction, as from the hand of God.
If a man purifies his heart and uproots from it all sin against the Lord; if he labors diligently to acquire Divine knowledge and succeeds in seeing with his mind that which is invisible to many, he must not through this exalt himself over others. Who among creatures is purer than an incorporeal being and who has more knowledge than an Angel? Yet, having exalted himself he was cast down from heaven like lightning. His pride was regarded by God as impurity.