I watched University Challenge last night as I try to do on Mondays. There was a question about woodwind instruments. I think the starter for 10 must have been Gabriel's oboe, which was quickly guessed. Knowing I am a big fan (I guess) they then played a clip of House of the King by Focus (which delighted me no end for some reason). Pan pipes was the inexplicable wrong answer (which no doubt left the question setter chuffed as I suppose the flute is being played by Van Leer in a slightly unorthodox way). They failed to get alto sax (Ron Crotty on Take Five I think) as they said Tenor Sax. They did recognise Acker Bilk's clarinet on Stranger on the Shore.
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.