Fasting, while of value in itself, is not something to boast of in front of God, for it is simply a tool for training those who desire self-restraint. The ascetic should not feel proud because he fasts; no artist ever boasts that his accomplishment is simply due to his tools; but he waits for the work itself to give proof of his skill.
God rests in holy places; that is (in) the Theotokos and all the Saints. These are they who have become likenesses of God as far as it is possible, since they have chosen to cooperate with divine election. Therefore, God dwells in them.
We ought to learn the virtues through practicing them, not merely through talking about them, so that by acquiring the habit of them we do not forget what is of benefit to us. 'The kingdom of God,' St. Paul says, 'resides not in words but in power' (I Cor. 4:20). For he who tries to discover things through actual practice will come to understand what gain or loss lies in any activity that he pursues.
For the washing away of bodily dirtiness God has given water. And for the washing of spiritual foulness, God has given the grace of the holy Sacrament of Confession. Every man, when he dirties his hands, washes them. No one says, 'I will not wash my hands anymore, because I will get them dirty again!' But why is it then that many people say, 'I will not go to Confession, because I will not sin again tomorrow!' It is clear that the enemy of our salvation is enticing us not to wash our souls, so that he can gain power over them.
It is always possible to make a new start by means of repentance. 'You fell,' it is written, 'now arise'(cf. Prov. 24:16). And if you fall again, then rise again, without despairing at all of your salvation, no matter what happens. So long as you do not surrender yourself willingly to the enemy, your patient endurance, combined with self-reproach, will suffice for your salvation. 'For at one time we ourselves went astray in our folly and disobedience,' says St. Paul. '... Yet He saved us, not because of any good things we had done, but in His mercy' (Tit. 3:3,5).
If you speak of pagan abuses, these abuses do not make our veneration of images loathsome. Blame the pagans, who made images into gods! Just because the pagans used them in a foul way, that is no reason to object to our pious practice. Sorcerers and magicians use incantations and the Church prays over catechumens; the former conjure up demons while the Church calls upon God to exorcise the demons. Pagans make images of demons which they address as gods, but we make images of God incarnate, and of His servants and friends, and with them we drive away the demonic hosts... If the Scripture says, The idols of the nations are silver and gold, the work of men's hands (Ps. 135:15), it is not forbidden to bow before inanimate things, or the handiwork of men, but only before those images which are the devil's work.
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.
The man who does not humble himself and does not cleanse his heart from evil desires fasts in vain. He may eat nothing at all, but it will be to no avail if there is evil inside him. He must first cleanse himself from the evil within in order to receive the Lord.
If we desire to acquire faith the foundation of all blessings, the door to God's mysteries, unflagging defeat of our enemies, the most necessary of all the virtues, the wings of prayer and the dwelling of God within the soul--we must endure every trial imposed by our enemies and by our many and various thoughts... if we forcibly triumph over the trials and temptations that befall us, it will not be we who are victorious, but Christ, Who is present in us through faith.
When God is thanked, He gives us still further blessings, while we, by receiving His gifts, love Him all the more and through this love attain that divine wisdom whose beginning is the fear of God (cf. Prov. 1:7).
Endurance is like an unshakeable rock in the winds and waves of life. However the tempest batters him, the patient man remains steadfast and does not turn back; and when he finds relief and joy, he is not carried away by self-glory: he is always the same, whether things are hard or easy, and for this reason, he is proof against the snares of the enemy.
He who is afraid of God's punishment has a slave-like fear of God, and it is this that makes him refrain from evil: 'Out of fear of the Lord men shun evil' (Prov. 16:6. LXX)... through fear of what threatens us we sinners may be led to repent and may seek deliverance from our sins...The more a man struggles to do good, the more fear grows in him, until it shows him his slightest faults, those which he thought of as nothing while he was still in the darkness of ignorance. When fear in this way has become perfect, he himself becomes perfect through inward grief: he no longer desires to sin but, fearing the return of the passions, he remains in this pure fear invulnerable. As the psalm puts it, 'The fear of the Lord is pure, and endures for ever' (Ps. 19:9. LXX). The first kind of fear is not pure, for it arises in us because of our sins. But, independent of sin, the person who has been purified continues to feel fear, not because he sins, but because, being human, he is changeable and prone to evil. In his humility, the further he advances through the acquisition of the virtues, the more he fears. This is natural; for everyone who possesses wealth greatly fears loss, punishment, dishonor, and the consequent fall from his high estate...The sign of the first kind of fear is hatred of sin and anger towards it, like someone wounded by a wild beast. The sign of perfect fear is the love of virtue and the fear of relapsing, since no one is unalterable.