By the end of the novel, Sebastian and Cordelia are also living stunted and sad lives. But, as happens so often in the fiction of Evelyn Waugh, a throwaway phrase contains the core of the novel’s meaning: “happiness doesn’t seem to have much to do with it.”
For Waugh, the notion that the life of faith ought to lead inevitably to worldly prosperity and what the pop psychologists call “wellness” is both unrealistic and dangerous. In a fallen world, afflicted by evil and stupidity, happiness can never be a gauge of fidelity to God. To think otherwise is to confuse happiness, with its bourgeois connotations of comfort and freedom from any burdens, with blessedness, or what Catholics call the “state of grace”. Catholics, Waugh believed, have always clung to the foot of the cross, profoundly and intuitively aware of what the Spanish philosopher Unamuno called “the tragic sense of life”.
As quoted in "Happiness Vs. Blessedness" by Ron Dreher (in The American Conservative)
H/T Wesley Hill's tumblr, writing in the dust