I'm a bit behind with this but I was sat listening again this last Lord's Day. We were in the Cardiff area after the wedding and stayed with relatives and so we went to their church, Emmanuel Baptist in Gabalfa, Cardiff. The preacher for the day was Dave Norbury who gently and winningly encouraged us from Scripture - from Psalm 78:19 in the morning and from Acts 6 in the evening. The first was a reminder of what God can do and the second a call to follow him. We also had a brilliantly told children's story in the morning. Dave Norbury has a background in education and Beach Missions and until recently was General Secretary of the EMW. In the evening my wife's brother-in-law interviewed him. I believe he is currently a member in Llanelli Free Church.
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.