We had a nice turn out to our kids clubs in church last night. Lots of funny things were said, mostly of a "you had to be there" sort. In the younger club I was speaking about Jesus's disciples and tried to explain how they weren't just with him in formal classroom type situaitons but followed him everywhere. One girl innocently asked if I meant "like stalking someone". No, that's not what I meant.
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.