Mary Mitchell Slessor (1848 – 1915) was an Aberdeen born missionary to Nigeria, where she worked among Efik people in the Clabar. Her work and strong personality allowed her to be trusted and accepted by the locals while spreading Christianity, including the promotion of omen's rights.
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.