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 culturehere. 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.
We all met up in Cardiff last Saturday for Gwïon's eighteenth. I was keen to have our five boys snapped together, something that we haven't done for a while.
Eleri obliged as I'm not great with a camera. I love them to bits. God is so good.