I should have mentioned that last Tuesday we went to see my son Gwion in a version of Shakepeare's The Tempest. It's not an easy play to follow but they did very well and Gwion is clearly following in the Brady thespian tradition.
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.