I went along last week to the John Owen Centre last week (my privilege as a graduate). The lecturer was Lane Tipton and around 8 or 9 of us were there for the lectures Monday to Friday (I had to miss Wednesday afternoon). Most are taking the course and are a good bunch. Dr Tipton's way is to lecture and allow questions and discussion with a session at the pub at the end of the day for those who wish. I got along twice to The Dignity in Church End, Finchley, and enjoyed the banter and the theology with a number of useful things coming out. I'm still getting the reading done so I was not best placed to benefit from the course. We hung quite loosely to the subject with lectures on systematics, Karl Barth and a lot of time on historical Adam and creation approaches but that was fine. It was a privilege to be there. The JOC has new drinks machines and that added to the ambience.
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.