Paul exhorts us, saying, “Rejoice in the Lord always, and again I say, rejoice” (Phil. 4:4). How is it possible to “rejoice always?” … Many words are not needed, nor a long round of argument, but if we only consider his expression, we shall find the way that leads to it. He does not simply say, “Rejoice always,” but he adds the cause of the continual pleasure, saying, “Rejoice in the Lord always.” He who rejoices “in the Lord,” cannot be deprived of the pleasure by anything that may happen. For all other things in which we rejoice are mutable and changeable, and subject to variation. And not only does this grievous circumstance attend them, but moreover while they remain they do not afford us a pleasure sufficient to repel and veil the sadness that comes upon us from other quarters. But the fear of God contains both these requisites. It is steadfast and immovable, and sheds so much gladness that we can admit no sense of other evils. For the man who fears God as he ought, and trusts in him, gathers from the very root of pleasure, and has possession of the whole fountain of joy. And as a spark falling upon a wide ocean quickly disappears, so whatever events happen to the man who fears God, these, falling as it were upon an immense ocean of joy, are quenched and destroyed!

Granted, Paul’s exhortation to “rejoice always” is a pretty tall order. Let John Chrysostom help you.