An absurd command

From "In Sickness and in Health":

Beloved, we are always in the wrong,
Handling so clumsily our stupid lives,
Suffering too little or too long,
Too careful even in our selfish loves:
The decorative manias we obey
Die in grimaces round us every day,
Yet through their tohu-bohu comes a voice
Which utters an absurd command--Rejoice.

~ W.H. Auden