Joy is the simplest form of gratitude.

...'joy' in Phillippians is a defiant 'Nevertheless!' that Paul sets like a full stop against the Philippians' anxiety...

Durch das Leid hindurch, nicht am Leid vorbei, geht der Weg zur Freude.

The theologian who labors without joy is not a theologian at all. Sulky faces, morose thoughts and boring ways of speaking are intolerable in this field.