Among my strongest memories of my grandparents involve food. My Nana Brady in particular was one from making trifles and milk jellies and was always providing cake and biscuits to go with the cuppa. My favourites then were custard creams and what I believe is called Genoa cake. As a child I would always split the custard cream, lick off the "cream" (or scrape it with the back of my front teeth) and then eat the biscuits. Glace cherries were always extracted from the slab of cake and eaten last.
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.