It is well known that obedience is the chief among the initiatory virtues, for first it displaces presumption and then it engenders humility within us. Thus it becomes, for those who willingly embrace it, a door leading to the love of God. It was because he rejected humility that Adam fell into the lowest depths of Hades. It was because He loved humility that the Lord, in accordance with the divine purpose, was obedient to his His Father even to the cross and death, although He was in no way inferior to the Father; and so through His obedience He has freed mankind from the crime of disobedience and leads back to the blessedness of eternal life all who live in obedience. Thus humility should be the first concern of those who are fighting the presumption of the devil, for as we advance it will be a sure guide to all the paths of virtue.
To act 'according to one’s strength' means to use a little less than necessary both of food, and drink, and sleep... As for food, restrain yourself when you wish to eat a little more, and in this way you will always make use of it moderately.
If you wish to be delivered from shameful passions, do not behave with anyone familiarly, especially with those toward whom your heart is inclined by a lustful passion; through this you will be delivered also from vainglory. For in vainglory is involved the pleasing of men, in the pleasing of men is involved familiarity of behavior, and familiarity of behavior is the mother of all passions.
When someone is beginning the spiritual life, he should not study a lot, but instead watch himself and guard his thoughts. A strong person is the one who chews well, not the one who eats a lot.
Concerning fasting, do not grieve, as I have said to you before: God does not demand of anyone labors beyond his strength. And indeed, what is fasting if not a punishment of the body in order to humble a healthy body and make it infirm for passions, according to the word of the Apostle: 'When I am weak, then am I strong' (II Corinthians 12:10).
The lower you descend, the higher you ascend; and when, like the psalmist, you regard yourself as nothing before the Lord (cf. Ps. 39:5), then imperceptibly you will grow great. And when you begin to realize that you have nothing and know nothing, then you will become rich in the Lord through the practice of the virtues and spiritual knowledge.
