I looked at that video again (which is here) and noticed that in the non-live there is a left handed drummer at the front. Someone else pointed out that at 02:02 you can see (in the top left hand corner) one poor drummer retrieving his sticks after dropping them. This is about making the video.
Bonhoeffer uses a similar phrase 'worldly Christianity'. It's J Gresham Machen that I want to line up most closely with. See his Christianity and culture here. Having done commentaries on Proverbs (Heavenly Wisdom) and Song of Songs (Heavenly Love), a matching title for Ecclesiastes would be Heavenly Worldliness. For my stance on worldliness, see 3 posts here.