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.
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).
All men are made in God's image; but to be in His likeness is granted only to those who through great love have brought their own freedom in subjection to God... Free will is the power of a deiform soul to direct itself by deliberate choice towards whatever it decides.
When you intend to do something and see that your thought is perturbed, and if after invoking God's Name it remains perturbed even by a hair's breadth, know from this that the action you mean to commit is from the evil one and refrain from commiting it. For nothing done with perturbation is pleasing to God.
If a righteous man can barely be saved, then where will I end up, I who am lawless and sinful? If the path that leads to life is strait and narrow, then how can I be vouchsafed such good things, I who live a life of luxury, indulging in my own pleasures and dissipation? But Thou, O Lord, my Saviour, Son of the true God, as Thou knowest and desirest it, by Thy grace alone, freely turn me away from the sin that abides in me and save me from ruin.
Woe is he who knowingly chooses to sin with the intention to repent when morning comes, for he knows not what the coming day or the night that precedes it will bring.
I wonder at our free will: it is strong, and yet it has been overthrown. It is a master, yet it has become a slave. It has the opportunity to conquer, yet it would rather yield and be conquered itself. Although it is free, it gives itself to slavery, like a bondswoman who signs with her own hand the agreement that binds her.
Go to the tombs and see that the assurance of men is nothing. Why then does man who is dust indulge in vainglory? Why does he who is all stench exalt himself? Let us therefore weep for ourselves while we have time, lest, at the hour of our departure, we be found asking God for extra time to repent.
For the complete fulfillment of its [the intellect's] purpose we should give it nothing but the prayer 'Lord Jesus'...Those who meditate unceasingly upon this glorious and holy name in the depths of their heart can sometimes see the light of their own intellect. For when the mind is closely concentrated upon this name, then we grow fully conscious that the name is burning up all filth which covers the surface of the soul; for it is written: 'our God is a consuming fire' (Deut. 4:24). Then the Lord awakens in the soul a great love for His glory...This is the pearl of great price which a man can acquire by selling all that he has, and so experience the inexpressible joy of making it his own.
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.
Those who meditate unceasingly upon the holy and glorious name [of Jesus] in the depths of their heart can sometimes see the radiance of their own spirit-intelligence. For when the mind is profoundly concentrated on this invocation, we feel experientially how it starts burning off all the layers of dirt that normally suffocates the soul.
When we fervently remember God, we feel divine longing well up within us from the depths of our heart. The evil spirits invade and lurk in the bodily senses, acting through the compliancy of the flesh upon those still immature in soul. According to the Apostle, our intellect always delights in the laws of the Spirit (cf. Rom. 7:22), while the organs of the flesh allow themselves to be seduced by enticing pleasures. Furthermore, in those who are advancing in spiritual knowledge, grace brings an ineffable joy to their body through the perceptive faculty of the intellect. But the demons capture the soul by violence through the bodily senses, especially when they find us faint-hearted in pursuing the spiritual path. They are, indeed, murderers provoking the soul to what it does not want.
If anyone wants to drive out the demons, he must first subdue the passions, for he will banish the demon of the passion which he has mastered. For example, the devil accompanies anger; so it you control your anger, the devil of anger will be banished. And so it is with each of the passions.
As wax cannot take the imprint of a seal unless it is warmed or softened thoroughly, so a man cannot receive the seal of God's holiness unless he is tested by labors and weaknesses. That is why the Lord says to St. Paul: 'My grace is sufficient for you: for My power comes to its fullness in your weakness'; and the Apostle himself proudly declares: 'Most gladly therefore will I rather glory in my weaknesses, so that the power of Christ may rest upon me' (2 Cor. 12:9).
The good Physician calls me and demands no payment, nor does he spill my blood. But my slothfulness prevents me from going to Him. He comes Himself to heal me, but always finds me engaged in acts that prevent His remedies from rendering me their healing power.
Whenever we enter the church and draw near to the heavenly mysteries, we ought to approach with all humility and fear, both because of the presence of the angelic powers and out of the reverence due to the sacred oblation; for as the Angels are said to have stood by the Lord's body when it lay in the tomb, so we must believe that they are present in the celebration of the Mysteries of His most sacred Body at the time of consecration.
