It was rather unusual yesterday in that I wasn't preaching but sat listening. I have an assistant at present, Andrew Lolley, and we are trying to have him preach quite often. I led the communion service to begin the day but then he preached - on Genesis 3 in the morning and the final part of the beatitudes in the evening and got on well. We had decent congregations at both services and one or two visitors which was nice. You learn things by sitting from time to time, rather than preaching.
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.