I was talking to someone about the American novel Pollyanna by Eleanor Porter the other day and so I selected it from the shelf and started to read it. It is not long and quite charming. The heroine is the orphaned daughter of a minister who plays a game based loosely on a biblical principle though more of the positive thinking variety. It's a charming and attractive story if a little saccharin in some ways. It first appeared in 1913 and several film adaptations have been made down the years.
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.