Habit forms from custom, and habit seems to accustom itself to nature. It is much worse and more difficult to change nature. However, with God it is possible. For nature does not set itself against God.
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.
Anyone who truly wants to follow God must be free from the bonds of attachment to this life. To do this we must make a complete break with our old way of life. Indeed, unless we avoid all obsession with the body and with the concerns of this world, we shall never succeed in pleasing God. We must depart as it were to another world in our way of thinking, as the Apostle said: 'Our citizenship is in heaven'. For the Lord said quite clearly: 'Any of you who does not renounce everything he cannot be my disciple'. Once we have managed to achieve this, we must remain ever on our guard to ensure that we never lose the thought of God, or destroy the memory of His wonders with our wandering minds. For we must keep the pure thought of God continually imprinted in our souls, as if it were an indelible seal.
The Christian ought not to be of doubtful mind, nor by anything drawn away from the recollection of God and of His purposes and judgments. The Christian ought in all things to become superior to the righteousness existing under the law, and neither swear nor lie. The Christian ought to be patient, whatever he has to suffer, and to convict the wrong-doer in season, not with the desire of his own vindication, but of his brother's reformation, according to the commandment of the Lord.
According to the degree to which the intellect is stripped of the passions, the Holy Spirit initiates the intellect into the mysteries of the age to be.
Trials are of two kinds. Either affliction will test our souls as gold is tried in a furnace, and make trial of us through patience, or the very prosperity of our lives will oftentimes, for many, be itself an occasion of trial and temptation. For it is equally difficult to keep the soul upright and undefeated in the midst of afflictions, as to keep oneself from insolence and pride in prosperity.
You can see that a city is prosperous by the wealth of goods for sale in the market. Land too we call prosperous if it bears rich fruit. And so also the soul may be counted prosperous if it is full of good works of every kind. But first of all it has to be farmed energetically. Then it must be watered by abundant streams of heavenly grace for it to bring forth fruit, some thirty fold, some sixty fold, and some a hundred fold. The soul only acquires goodness and the capacity of fulfilling its duties if it has the grace of God On the other hand, what is uglier or more disgusting than a soul given over to base passions? Look at the hot-headed person: he is like a wild beast. Consider the slave of lust or gluttony: who can bear the sight of him? Pity the victim of melancholy whose spirit is totally prostrated. It is for us to seek to acquire beauty so that the Bridegroom, the Lord, may welcome us into his presence and say, “You are utterly fair, my love, and there is no flaw in you.” (Song of Sol 4:7)
The Lord ordereth 'all things in measure and weight,' and brings on us the temptations which do not exceed our power to endure them, but tests all that fight in the cause of true religion by affliction, not suffering them to be tempted above that they are able to bear.
Be slow and dull to idle talk, but knowing and wise in hearkening to the saving words of the Holy Scriptures. Let the hearing of worldly tales be to you as a bitter taste in your mouth, but the discourse of holy men as a honeycomb (Prov. 16.24). Be eager to imitate men of disciplined habits and do not wait to be taught each thing. Strive to attain to the greater virtues, but do not neglect the lesser ones. Do not make light of a fall even if it be the most venial of faults; rather, be quick to repair it by repentance, although many others may commit a large number of faults, slight and grievous, and remain unrepentant. Judge not the sins of others, for they have a just Judge ‘Who will render every man according to his works’ (Rom. 2.6); but be master of what is your own and lighten your own burden insofar as you have the power, for he who increases his own burden will also carry it. In repentance is salvation, but folly is the death of repentance.