I had quite a cultural day in the nation's capital yesterday. First I got myself down to the Courtauld Gallery (its half price on Mondays). There is a summer exhibition at the moment on Gauguin. Most of the artefacts are on permanent display but the exhibition (of five paintings, a sculpture, some prints and a few other things) is done well. See more here.
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.