Robert Erskine Childers DSC (1870–1922), universally known as Erskine Childers, was the author of the influential novel The Riddle of the Sands a novel I have not read but am always intending to get round to. It has never gone out of print and is often cited in top novel lists. They say it was the first spy novel. An Irish nationalist he smuggled guns to Ireland in his sailing yacht Asgard. He was executed by the authorities of the nascent Irish Free State during the Irish Civil War. He was the son of British Orientalist scholar Robert Caesar Childers; the cousin of Hugh Childers and Robert Barton; and the father of the fourth President of Ireland, Erskine Hamilton Childers.
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.