I was reading Acts 15 this morning, which mentions Judas Barsabbas. The name rang a bell. Wasn't he mentioned in Acts 1? No, that was Joseph Barsabbas, his brother perhaps. Looking for more info I came across this interesting article here. The whole site is interesting though probably incorrect at several points. What do you think?
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.