Lyric discussion by stayfluffy 

Cover art for Slumber lyrics by Bad Religion

I don't think this song is sarcastic. I think it was intended to be comforting, just look at the lyrics:

Knowing we're all in this together, For such a short time anyway.

There's just no time to parade around sulking, I would rather laugh than cry, The rich the poor the weak we share this place together

He's dead on on all of that, no sarcasm. Anyways I feel that this is a very uplifting song.