Our second session was led by Maurice Roberts who looked at the subject of the justice of God. This was a little diffuse but reminded us of essential truths such as the remunerative and retributive nature of God's justice, the sinfulness of sin (original, depravity and actual sin), repentance, faith in Christ, justification and judgement.
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.