We're getting to the end of term here and so I've just been to see my eldest in the school production of Lionel Bart's Oliver (a life-long love of his) set in the seventies. He played the rather nasty Bill Sykes. A triumph! They were all pretty good, especially Nancy and Fagin.
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.