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.
Reformation Boise Conference - 2018
Thought you might like to see this as it not only advertises a conference in the church where my son currently attends but he had a big hand in putting the video together (look out for the young man in the green hoody). For more info see here