I'm just back from a prayer breakfast of the church. Six of us gathered for a time of prayer followed by a cuppa and doughnuts. It is the traditional final meeting of our week of prayer which we try and hold in early Spring and early Autumn. When I get it right we have an early morning prayer meeting, a mid morning one, two evening ones, often an extra early morning one and then the prayer breakfast. It helps to focus again on prayer. This time round a notional 35 or so people attended six prayer meetings (some 21 or so individuals in reality who came to at least one meeting).
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.