I was slightly nervous about yesterday as my esteemed father-in-law was in the congregation and we had a novice pianist playing. We also had quite a few people away and the number of children present was in double figures, which is rare for us. Despite all this we had a good day beginning with communion and then carrying on with 1 Corinthians 2 in the morning and Numbers 29 in the evening. The first passage was full of good things but extraction was more difficult with the second.
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.