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.
You must set about rooting out the very desire to have things pleasant, to get on well, to be contented. You must learn to like sadness, poverty, pain, hardship. You must learn to follow privately the Lord's bidding: not to speak empty words, not to adorn yourself, always to obey authority, not to look at a woman with desire, not to be angry and much else. For all these biddings are given us not in order for us to act as if they did not exist, but for us to follow: otherwise the Lord of mercy would not have burdened us with them. If any man will come after me, let him deny himself, He said (Matthew 16:24), thereby leaving it to each person's own will ... and to each person's endeavor: let him deny himself.
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.
You are, I am sure, aware that for you penitence is now no longer limited to disclosing your sins to your confessor, but that you must now bear your sins in mind always, until your heart nearly breaks with their ugly load; and would break, were it not for your firm faith in the mercy of our Lord.
Remember that a good action is always either preceded or followed by temptations. God permits this so that the virtue, exercised in that particular action, may be confirmed, consolidated, steeled.
You are, I am sure, aware that for you penitence is now no longer limited to disclosing your sins to your confessor, but that you must now bear your sins in mind always, until your heart nearly breaks with their ugly load; and would break, were it not for your firm faith in the mercy of our Lord.
God smiles on the compassionate heart. Every time a beggar knocks at your door, try to perceive Christ Himself under the humble disguise. Would you, under any circumstances, let Christ knock in vain? The moral qualities of the individual beggar have nothing to do with it; that is Christ's concern, not yours. Who are you to judge your brother? Christ is using the beggar’s hand and mouth to test your compassion of Himself. Will you fail Him?
A prayer offered while one has any cause to reproach a fellow man is an impure prayer. There is only one whom the praying person may and must reproach, and that is himself. Without self-reproach, your prayer is as worthless as it is while you are reproaching someone else in your heart. Perhaps you ask: How can one learn this? The answer is: One learns it through prayer.
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.
Keep your conscience keen and bright, and refrain from hankering after, or expecting, consolation. Leave that to God. He knows when, where, and how to give it to you.
The weather shifts from cloudy to clear and then back to rain; thus it is with human nature. One must always expect clouds to hide the sun sometimes. Even the saints have had their dark hours, days and weeks. They say then that 'God has left them' in order that they may know truly how utterly wretched they are of themselves, without His support. These times of darkness, when all seems meaningless, ridiculous and vain, when one is beset by doubt and temptations, are inevitable. But even these times can be harvested for good. The dark days can best be conquered by following the example of St. Mary of Egypt. For forty-eight years she dwelt in the desert beyond Jordan, and when temptations befell her and memories of her former sinful life in Alexandria beckoned her to leave her voluntary sojourn in the desert, she lay on the ground, cried to God for help and did not get up until her heart was humbled. The first years were hard; she sometimes had to lie this way for many days; but after seventeen years came the time of rest. On such days stay quiet. Do not be persuaded to go out into social life or entertainment. Do not pity yourself, seek comfort in nothing but your cry to the Lord: 'Haste thee, O God, to deliver me! Makes haste to help me, O Lord (Psalm 70:1)! I am so fast in prison that I cannot get forth (Psalm 88:8),' and other such appeals. You cannot expect real help from any other source. For the sake of chance relief do not throw away all your winnings. Pull the covers over your head; now your patience and steadfastness are being tried. If you endure the trial, thank God who gave you the strength. If you do not, rise up promptly, pray for mercy and think: I got what I deserved! For the fall itself was your punishment. You had relied too much on yourself, and now you see what it led to. You have had an experience; do not forget to give thanks.
Do not think that even here any one of us constantly enjoys consolation. No: here, as everywhere, flesh and mind are at war; here as everywhere, there is falling into pride and purification through humbling: here, as everywhere, we long for consolations but must learn to carry a weighty cross. This cross tests our love. Can we, do we love God even under the weight of the most bitter adversities?
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.
The Holy Fathers recommend 'moderate' fasting; one ought not to allow the body to be weakened too much, for then the soul, too, is harmed. Nor ought one to undertake fasting too suddenly; everything demands practice, and each one should look to his own nature and occupation. To choose among different kinds of food is to be condemned; all food is God-given, but it is advisable to avoid such kinds as add to the body's weight and appetite; strong spices, meat, spirituous drinks and such foods as are solely for the palate's enjoyment. For the rest, one may eat what is cheap and most easily available, they say. But by 'moderate' they mean one meal a day, and that one light enough not to fill the stomach to satiety.