I went with my father-in-law yesterday up the road to Llandrindod Wells to the Pavilion where the Keswick in Wales convention has been taking place this last week. The main speaker has been John Tindall and we heard him very helpfully on the woman who anointed Jesus at Simon's house. After a nice meal at the Metropole and a wander around Llandrindod we heard Ben Thomas preach on the end of Romans 8. Again, it was very good (although I nodded off at one point tired from yesterday). There must have been about a hundred there, most of them unknown to me though I had nice chats with the few I do know. Nice day.
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.