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.
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.
But if you are fearful of becoming self-righteous from working for your own salvation, or afraid of being overcome by spiritual pride, examine yourself and observe that the person who is afraid of becoming self-righteous suffers from blindness. For he does not see how self-righteous he is.
Be careful not to neglect the small things, take care not to despise them as something insignificant. They are not insignificant; they are cancer for the soul, a bad habit. Let us therefore be vigilant. Let us pay attention to slight things, whilst they are still slight and before they become serious. Both the life of holiness and the sinful life start from little things and lead to greater ones, either good or bad.
One should not ponder divine matters on a full stomach, say the ascetics. For the well-fed, even the most superficial secrets of the Trinity lie hidden.
Jesus Christ said that the Holy Spirit blows where it wills and you hear the sound of it, but cannot tell where it comes from and where it goes (Jn. 3:8). This means that a person cannot force the Holy Spirit to come to him or predict the time when He may decide to do so. You can only feel His touch when this happens. Indeed, the book of Acts states that when the Holy Apostles and other Christians received the gifts of the Holy Spirit, it was always unexpectedly. He seldom descends immediately on those beseeching Him but does so when it suits Him, as God, to do so. No one should attempt to foretell when or what gifts, if any, he will receive or to consider himself worthy of His descent! The Grace of the Holy Spirit is a gift of His endless mercy. And gifts by definition are given when it suits the giver, and only those deemed suitable by the giver.
The person who truly comes to serve God must prepare his soul, as it says in the Wisdom of Sirach (2:1), for temptations. Thus, that he will never be surprised or disturbed by what happens, believing that nothing happens without the providence of God and where there is the providence of God certainly what happens is good and for the benefit of the soul. For, everything that God does, He does for our benefit and because He loves us and has pity on us. We must, as the Apostle says, 'In everything give thanks' (1 Thess. 5:18), for His goodness.
For this world is opposed to the world above, and this present age to the eternity above. The Christian therefore, according to Holy Scripture, must deny the world, and be translated and pass in mind out of this present age, in which the mind is placed and exposed to allurements ever since the transgression of Adam, into another age, and in frame of thought must live in the world of the Godhead above, as it is said, But our conversation is in heaven. (Phil. iii. 20.).
This is the mark of Christianity--however much a man toils, and however many righteousnesses he performs, to feel that he has done nothing, and in fasting to say, 'This is not fasting,' and in praying, 'This is not prayer,' and in perseverance at prayer, 'I have shown no perseverance; I am only just beginning to practice and to take pains;' and even if he is righteous before God, he should say, 'I am not righteous, not I; I do not take pains, but only make a beginning every day.'