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.
God the Word, the God-Man, our Lord Jesus Christ, compares our life with a market, and the work of our life on earth He calls trading, and says to us all: Trade till I come (Luke 19:13), redeeming the time, because the days are evil (Ephesians 5:16). That is to say, make the most of your time for getting heavenly blessings through earthly goods. Earthly goods are good works done for Christ's sake and conferring on us the grace of the All-Holy Spirit.
Unless curbed by the fear of God that accompanies the practice of the virtues, spiritual knowledge leads to vanity; for it encourages the person puffed up by it to regard as his own what has merely been lent to him, and to use his borrowed intelligence to win praise for himself. But when his practice of the virtues increases concomitantly with his longing for God, and he does not arrogate to himself more spiritual knowledge than is needed for the task in hand, then he is made humble, reduced to himself by principles which are beyond his capacity.
