Peter was first given the keys, but then he was allowed to fall into the sin of denying Christ; and so his pride was humbled by his fall. Do not be surprised, then, if after receiving the keys of spiritual knowledge you fall into various evil thoughts. Glorify our Lord, for He alone is wise: through setbacks of this kind He restrains the presumption that we tend to feel because of our advance in the knowledge of God. Trials and temptations are the reins whereby God in His providence restrains our human arrogance.
Imitate the Publican and you will not be condemned with the Pharisee. Choose the meekness of Moses and you will find your heart which is a rock changed into a spring of water.
A treasure that is known is quickly spent: and even so any virtue that is commented on and made a public show of is destroyed. Even as wax is melted before the face of fire, so is the soul enfeebled by praise, and loses the toughness of its virtue.
Abba Ammonas came one day to eat in a place where there was a monk of evil repute. Now it happened that a woman came and entered the cell of the brother of evil reputation. The dwellers in that place, having learnt this, were troubled and gathered together to chase the brother from his cell. Knowing that Bishop Ammonas was in the place, they asked him to join them. When the brother in question learnt this, he hid the woman in a large cask. The crowd of monks came to the place. Now Abba Ammonas saw the position clearly but for the sake of God he kept the secret; he entered, seated himself on the cask and commanded the cell to be searched. Then when the monks had searched everywhere without finding the woman, Abba Ammonas said, 'What is this? May God forgive you!' After praying, he made everyone go out, then taking the brother by the hand he said, 'Brother, be on your guard.' With these words, he withdrew.
'Then the devil left Him, and angels came and ministered to Him' (Matthew 4:11). It does not say that the angels were with our Lord during the actual time when He was being tempted. In the same way, when we are being tempted, God's angels for a time withdraw a little. Then, after the departure of those tempting us, they come and minister to us with divine intellections, giving us support, illumination, compunction, encouragement, patient endurance, joyfulness, and everything that saves and strengthens and renews our exhausted soul. As Nathaniel was told, 'You will see the angels ascending and descending upon the Son of man' (John 1:51); in other words, the ministry and assistance of the angels will be given generously to mankind.
Rivalry over material possessions has made us forget the counsel of the Lord, who urged us to take no thought for earthly things, but to seek only the kingdom of heaven (cf. Matt. 6:33).
It is more serious to lose hope than to sin. The traitor Judas was a defeatist, inexperienced in spiritual warfare; as a result he was reduced to despair by the enemy's onslaught, and he went and hanged himself. Peter, on the other hand, was a firm rock: although brought down by a terrible fall, yet because of his experience in spiritual warfare he was not broken by despair, but leaping up he shed bitter tears from a contrite and humiliated heart. And as soon as our enemy saw them, he recoiled as if his eyes had been burnt by searing flames, and he took flight...
BROTHER: Behold, through what have the men of old triumphed? OLD MAN: Through the fervor of their supernatural love, and through the death of the corruptible man, and through the contempt for pride, and through the abatement of the belly, and through the fear of the judgement, and through the promise of certainty; through the desire for these glorious things the fathers have acquired in the soul the spiritual body.
In the beginning, there is struggle and a lot of work for those who come near to God. But after that, there is indescribable joy. It is just like building a fire: at first it's smoky and your eyes water, but later you get the desired result. Thus we ought to light the divine fire in ourselves with tears and effort.
If a king wanted to take possession of his enemy's city, he would begin by cutting off the water and the food and so his enemies, dying of hunger, would submit to him. It is the same with the passions of the flesh; if a man goes about fasting and hungry the enemies of his soul grow weak.
And the old man also said, 'God saith unto thee thus -- if thou lovest Me, O monk, do that which I ask, and do not that which I do not desire. For monks should lead lives wherein they act not in iniquity, and a man should not look upon evil things with his eyes, no hear with his ears things which are alien to the fear of God, nor utter calumnies with his mouth, nor plunder with his hands; but he should give especially to the poor, and he should not be unduly exalted in his mind, and he should not think evil thoughts, neither should he fill his belly. Let him do then all these things with discretion, for by them is a monk known.' The old man also said, 'These things form the life of a monk: good works, and obedience, and training. A man should not lay blame on his neighbor, and he should not utter calumnies, and he should not complain, for it is written, 'The lovers of the Lord hate wickedness.'
He who wishes to tear up the account of his sins and to be inscribed in the Divine book of the saved, can find for this purpose no better means than obedience.