I woke up Friday morning to find the internet out (and the phone line too). It was another 50 hours or so before it was sorted out some time on Sunday. Thankfully mobile phones allowed us to report the fault and get calls diverted so we managed okay, which I am relieved to be able to say.
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.