We looked at the Tree of the knowledge of good and evil in Genesis 2 and 3 last night. I've been thinking about it since the week on Covenant Theology. The subject of the trees in the garden is often taken up by supporters of the Adamic covenant of works, although plenty can be said without getting into that issue. There were twelve of us present and there was plenty to pray about as ever. I'll probably look at the Tree of Life next week.
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.