Our final session from Dr Chirico was a powerpoint presentation on Vatican II. He very helpfully took us through the deceptive and equivocal approach of the Roman church since Vatican II. He went through some of the various documents and pointed out the yes no approach that blurs the whole scene. These three messages have been very helpful.
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.