I'm not sure how long Rosevelt and Churchill have been sat outside the Catto Gallery in Hampstead. They have acquired a new friend, however. I first saw her, I think, around Hallowe'en in a bin. They both seem to like her.
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.