Man, man is the great instrument that produces wealth. The natural difference between Campania and Spitzbergen is trifling when compared with the difference between a country inhabited by men full of bodily and mental vigour, and a country inhabited by men sunk in bodily and mental decrepitude. Therefore it is that we are not poorer but richer, because we have, through many ages, rested from our labour one day in seven. That day is not lost. While industry is suspended, while the plough lies in the furrow, while the Exchange is silent, while no smoke ascends from the factory, a process is going on quite as important to the wealth of nations as any process which is performed on more busy days. Man, the machine of machines, the machine compared with which all the contrivances of the Watts and the Arkwrights are worthless, is repairing and winding up, so that he returns to his labours on the Monday with clearer intellect, with livelier spirits, with renewed corporal vigour. Never will I believe that what makes a population stronger, and healthier, and wiser, and better, can ultimately make it poorer.Part of a speech given on May 22, 1846, in the House of Commons
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.