Truly wretched and three times miserable is the soul that has left the world and dedicated itself to God but has not lived in a manner worthy of its promise. Then, brothers, let us not allow this age, which is short and contemptible and passes like a shadow, to steal that blessed and immortal life away from us.
If you want cure your soul, you need four things. The first is to forgive your enemies. The second is to confess thoroughly. The third is to blame yourself. The fourth is to resolve to sin no more. If we wish to be saved, we must always blame ourselves and not attribute our wrong acts to others. And God, Who is most compassionate, will forgive us.
Do not neglect the practice of the virtues; if you do, your spiritual knowledge will decrease, and when famine occurs you will go down into Egypt (Genesis 41:57, 46:6).
You write that after Communion you felt well. Glory be to God, Who comforts our unworthiness. And as regards the fact that this soon passed, here also is seen His fatherly providence for us. For continual consolation enfeebles the soul and makes it slothful, or leads to even greater harm. That is why the Lord takes it away quickly and again makes us feel our weakness, our helplessness, and our sinfulness. We must humble ourselves more, reproach ourselves, offer repentance for our sins, and not desire consolations, but patiently endure what God allows. Dryness and cooling of fervor are also permitted on account of vainglory.
Tedium is the granddaughter of despondency, and the daughter of slothfulness. In order to drive it away, labor at your work, and do not be slothful in prayer. The tedium will pass, and zeal will come. And if to this you add patience and humility, then you will be rid of all misfortunes and evils.
You must flee from sensual things. Verily, every time a man comes close to a struggle with sensuality, he is like a man standing at the edge of a deep lake, and the enemy throws him in whenever he likes. But if the man lives far from sensual things, he is like one who stands at a distance from the lake, so that even if the enemy entices him in order to throw him to the bottom, God sends him help at the very moment that the enemy is drawing him away and doing him violence.
I must tell you that annoying incidents are unavoidable in this life. Those who are experienced in the spiritual life say that such incidents can even bring profit to the soul. Through annoying incidents we come to recognize that we are impatient - and if we are impatient, that means we are proud. And this awareness should dispose us to self-reproach and repentance, and to asking mercy from the Lord in prayer. But without annoying incidents a man is inclined to conceit.