Okay last one. I haven't mentioned the rugby this six nations as although Wales have won two of three games they haven't been playing at their best. I came across this the other day, though, and thought I might pop it on here. Look out for one of the few B&W sections and an utterly amazing try by the previously mentioned Keith Jarrett.
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.