I recently saw the book Snow by Marcus Sedgwick (not a name I knew though he is a fairly well known author) and fell in love with it. It is only just over a hundred pages so I had it read in no time. It just talks about snow which might not seem very appealing to some but for me it was brilliant. To read Sedgwick giving the etymology of the word snow sent me into a minor ecstasy I must admit. That first of six brief chapters (Snow talk) I enjoyed the most but the whole little hardback is lovely, especially for this time of year. I have another little book called Snow. That one is by Maxence Fermine and is a piece of fiction. I must read it again.
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.