What happened to the series on childhood songs I don't hear you ask? This one was not in Singing Together like the others but it is clearly a childhood song. I distinctly remember hearing it for the first time. I'd not been attending school long when I had my first experience of a wet lunch time. The dinner ladies (they all seemed to wear pink nylon overalls in those days) gathered us into a corridor where we sat on wooden benches and sang. We must have sung other things but this one was totally new to me and seemed to be of an exotic flavour that quite blew me away. I think what added to it was that everyone else seemed to know it. The clip above is not the version I learned exactly but it gives you the idea.
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.