Sir Henry Rider Haggard (1856 –1925) was an English writer of adventure novels set in exotic locations, predominantly Africa, and a founder of the Lost World literary genre. He was also involved in agricultural reform throughout the British Empire. His stories, situated at the lighter end of Victorian literature, continue to be popular and influential. His earliest novels are his most famous - King Solomon's Mines (1885) Allan Quatermain (1887) She (1887) Cleopatra (1889). He wrote many more right up until 1921.
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.