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.
When you shed floods of tears during prayer, do not exalt yourself for this, as though you were above many others. It is that your prayer has received help from above, so that, having zealously confessed your sins, you may incline the almighty to mercy by your tears.
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.
Many do good actions, but neglect the mind; they know nothing of the spiritual contests, the victories and defeats. They neglect the mind which is the eye of the soul.
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 the highest aim of virtue is that which aims at the advancement of most, gentleness is the most lovely of all, which does not hurt even those whom it condemns, and usually renders them whom it condemns worthy of absolution.
True joy is the joy of consolation, the joy that wells up in the knowledge of one's own weakness and the Lord's mercy, and that does not need the bared teeth of laughter to express itself.
But there is hardly anything more serious than to be joined in marriage to a stranger (i.e., to an unbeliever), where the instigations both of lustful appetite and of disharmony and the shameful crimes of sacrilege are welded together. For if marriage itself needs to be sanctified by the priestly veil and blessing, how is it possible to speak of a marriage where there is no agreement in faith?
Go, sell all that belongs to you and give it to the poor and taking up the cross, deny yourself; in this way you will be able to pray without distraction.
Therefore we must not grow weary. We must be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord our labor is not in vain (I Corinthians 15:58). Having once begun, we must not cease to perform deeds worthy of our repentance. To rest is the same as to retreat.
Be fond of working with your hands, but still more of the memory of prayer; because the first does not always bring us the fruit of that occupation, while the second does so unceasingly. Do not stop praying until you have paid your due of prayer in full, and do not listen to the thought that it is time to sit down to work. Equally, when you sit at work, do not be too concerned in it, lest you agitate the heart by your haste and make it worthless for prayer.