Providentially we have had two Jewish people speaking at the church in the last few days about the work of the gospel among their people. First Andreea came to our midweek meeting to speak about the work she has been involved in over the last 18 months adn then yesterday evening David Zadok was with us speaking about the work of HaGefen publishing and preaching from Psalm 121. Living as we do in an area that is 15% Jewish it was good to be reminded to pray and to know that many Jewish people are showing an interest in these things and coming to know Messiah for themselves in many cases too. For more info check these sites here and here.
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.