I am enjoying the new biography of the Puritan Arthur Hildersham by Leslie Rowe. I notice that not only did he preach 152 sermons on Psalm 51 but he spent nine sermons on the heading. Those were the days!
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.