God often permits virtuous men to be tried by something: He permits temptations to rise up against them on all sides... Whether these trials come from men, demons or flesh, let it be a cause for thanksgiving. For God cannot show his favor to a man who desires to dwell with Him, except by sending him trials for the sake of truth; just as no man can become worthy of this greatness... without the grace of Christ... St. Paul plainly calls it a gift... 'For unto you it is given in behalf of Christ, not only to believe in Him, but also to suffer for His sake' (Phil. 1:29).
The most important thing during illness is to offer to God patience and thanksgiving for His merciful visitations. Sickness purifies sins and gives one time to meditate on the past.
If you wish to be delivered from shameful passions, do not behave with anyone familiarly, especially with those toward whom your heart is inclined by a lustful passion; through this you will be delivered also from vainglory. For in vainglory is involved the pleasing of men, in the pleasing of men is involved familiarity of behavior, and familiarity of behavior is the mother of all passions.
But where does Christ dwell? In pure hearts, hearts that are humble and contrite, there where He is not grieved by doubt or unbelief, by indifference towards Him, Who is God and Savior; there where men do not prefer the temporal sweetness of sin; where the idols of the passions have been chased out; where crude materiality is not preferred to the Kingdom of God, where Christians often turn their thoughts to the heavenly, as those created for heaven, for eternity; there where they seek God's truth, where every day and every hour they are attentive to His commandments. Here is where Christ dwells. And what does He do there? If only we knew (some, of course, do know) what He does in souls worthy of His abiding presence--what rest, comfort and joy He imparts, what paradisical bliss He gives them to experience while still on this earth.
So long as the soul is sick with passions, its senses have no perception of the spiritual; and the soul does not even know how to desire it, but desires it only from hearsay and writings. The power of the soul is cured of these diseases by the hidden practice of commandments, with sharing in Christ's passion.
Read often and insatiably the books of the teachers of the Church on divine providence, for they lead the mind to discern the order in God’s creatures and His actions, give it strength, and by their subtleness they prepare it to acquire luminous intuitions and guide it in purity toward understanding of God’s creatures. Read also the Gospels, which God ordained for knowledge for the whole world, that you may find provisions for your journey in the might of God’s providence for every generation, and that your intellect may plunge deeply into wonder at Him. Such reading furthers your aim. Let your reading be done in a stillness which nothing disturbs; be free of all concern for the body and the turmoil of affairs, so that through the sweet understanding which surpasses all the senses you may savor that most sweet taste in your soul which she perceives in herself because of her constant intercourse with these things.
Reverence with all the powers of your soul all the sacraments, and say to yourself in respect to every sacrament before the celebration or the communion of it: `This is God's mystery. I myself am only the unworthy witness or partaker of it.' Otherwise our proud intellect even wishes to search out God's mystery, and, if unable to penetrate it, rejects it as not coming under the small measure of our intellect.
Most men not only bear Satan's burden willingly in their hearts, but they become so accustomed to it that they often do not feel it, and even imperceptibly increase it. Sometimes, however, the evil enemy increases his burden tenfold, and then they become terribly despondent and fainthearted, they murmur and blaspheme God's name. The usual means that men... take to drive away their anguish are... entertainments... But such means afterwards increase still more the anguish and weariness of their hearts. If, happily, they turn to God, then the burden is removed from their heart, and they clearly see that previously the heaviest burden was lying on their heart, though frequently they did not feel it.
Most people desire and seek after prosperity in this life, and they strive to avoid sorrows. While that seems very good and pleasant, constant prosperity and good fortune do a person harm. He falls into a variety of passions and sins, and angers the Lord, while those who live a life of sorrow come closer to the Lord and more readily attain unto salvation, for the Lord called the life of happiness the broad path. The wide gates and the broad way lead to destruction, and many there be who take that way (Matthew 7:13). It is the narrow way and the strait gate which lead to life eternal, and few there be who find it (Matthew 7:14). Thus, according to His love for us, seeing the possible benefit [of sorrows] to those who are worthy, the Lord moves many off the broad road and puts them on the narrow, sorrowful path, so that in [their] patient endurance of sickness and sorrow, He might effect their salvation and grant them life eternal.
When praying, endeavor by every means to feel in your heart the truth and the power of the words of the prayer; feed yourself upon them as upon an imperishable food; water your heart with them as with a dew; and warm yourself by them as by means of a beneficial fire.
Do not be despondent when fighting against the incorporeal enemy, but even in the midst of your afflictions and oppression praise the Lord, Who has found you worthy to suffer for Him, by struggling against the subtlety of the serpent, and to be wounded for Him at every hour; for had you not lived piously, and endeavored to become united to God, the enemy would not have attacked and tormented you.
Not he is chaste in whom shameful thoughts stop in time of struggle, work and endeavor, but he who by the trueness of his heart makes chaste the vision of his mind not letting it stretch out towards unseemly thoughts.
Your past and present torments and sufferings are poured down upon you to test your faith and 'steel' it; they also work to curb your lusts and passions. Humble yourself. God gives help to the humble. Judgment of others, insistence on their shortcomings, can only increase the bitterness of your sorrow. Choose the better part.