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.
The hour of death will come upon us, it will come, and we shall not escape it. May the prince of this world and of the air (cf. John 14:30; Eph. 2:2) find our misdeeds few and petty when he comes, so that he will not have good grounds for convicting us. Otherwise we shall weep in vain. 'For that servant who knew his lord's will and did not do it as a servant, shall be beaten with many stripes' (cf. Luke 12:47).
The humility which in due time and by God's grace, after many struggles and tears, is given by heaven to those who seek it is something incompararably stronger and higher than the sense of abasement felt by those who have lapsed from holiness. This higher humility is granted only to those who have attained true perfection and are no longer under the sway of sin.
A great effort and much toil are needed in prayer before we can reach a state in which our mind is no longer troubled, and so attain the inward heaven of the heart where Christ dwells. As St. Paul says, 'Do you not realize that Christ dwells within you, unless you are worthless?' (cf. 2 Cor. 13:5).
Our Lord and God made flesh has offered us the image of all virtue, as an example to the human race; and to recall us from the ancient fall, has set before us, as in a picture, His all-virtuous life in the flesh. Among many other good examples, He has shown us how, after His baptism, when He went out into the wilderness, it was with fasting that He began His mental wrestling with the devil, who came against Him as an ordinary man. And through this manner of His victory, our Lord has taught us, His unprofitable servants, how we must practice our wrestling against the spirits of evil, that is with humility and fasting and prayer and sobriety: which He observed though He Himself had no need of such things, being God...
When anyone is disturbed or saddened under the pretext of a good and soul-profiting matter, and is angered against his neighbor, it is evident that this is not according to God: for everything that is of God is peaceful and useful and leads a man to humility and to judging himself.
There is no venom more poisonous than that of the asp or cobra, and there is no evil greater than that of self-love. The winged children of self-love are self-praise, self-satisfaction, gluttony, unchastity, self-esteem, jealousy and the crown of all these, pride. Pride can drag down not men alone, but even angels from heaven, and surround them with darkness instead of light.
Fire makes iron impossible to touch, and likewise frequent prayer renders the intellect more forceful in its warfare with the enemy. That is why the demons strive with all their strength to make us slothful in attentiveness to prayer, for they know that prayer is the intellect's invincible weapon against them.
If the base of a felled tree that has grown old in the earth and rock ‘will bud at the scent of water . . . like a young plant’ (Job 14:9), it is also possible for us to be awakened by the power of the Holy Spirit and to flower with the incorruptibility that is ours by nature, bearing fruit like a young plant, even though we have fallen into sin.
It is impossible for the soul to attain anything spiritual and pleasing to God, or to be free of inner sin, without guarding of the mind and purity of heart, in other words, without sobriety... If with God's help we gain something daily through our sobriety, we should take care not to enter into communication with other people without discrimination, lest we suffer loss through our converse with them and are led into temptation.
Whenever we are filled with evil thoughts, we should throw the invocation of our Lord Jesus Christ in their midst. Then, as experience has taught us, we shall see them instantly dispersed like smoke in air. Once the intellect is left to itself again, we can renew our constant attentiveness and our invocation. Whenever we are distracted, we should act in this way.
Compunction comes when you consider how much you have grieved God Who is so good, so sweet, so merciful, so kind, and entirely full of love; Who was crucified and suffered everything for us. When you meditate on these things and other things the Lord has suffered, they bring compunction.
Prayer... by its action it is the reconciliation of man with God, the mother and daughter of tears, a bridge for crossing temptations, a wall of protection from afflictions, a crushing of conflicts, boundless activity, the spring of virtues, the source of spiritual gifts, invisible progress, food of the soul, the enlightening of the mind, an axe for despair, a demonstration of hope, the release from sorrow.
Do all in your power not to fall, for the strong athlete should not fall. But if you do fall, get up again at once and continue the contest. Even if you fall a thousand times because of the withdrawal of God's grace, rise up again each time, and keep on doing this until the day of your death. For it is written, 'If a righteous man falls down seven times' - that is, repeatedly throughout his life - 'seven times shall he rise again' [Prov. 24:16].
Fear God and keep His commandments both in your feelings and in your intellect. If you force yourself to keep them in your intellect, bit by bit you will attain to fulfilling them in your feelings.