I once heard a story from a soldier who...had laid siege against a fort, that so long as the besieged were persuaded their foes would show them no favour, they fought like madmen. But when they saw one of their fellows taken and received with favor, they all came tumbling down from their fortress and delivered themselves into their enemies’ hands. I am persuaded that if men believed that there is that grace and willingness in the heart of Christ to save sinners, as the Word imports there is, they would come tumbling into His arms. But Satan has blinded their minds so that they cannot see this thing. Nevertheless, the Lord Jesus has, as I said, that others might take heart and come to Him, given out a commandment that mercy should,in the first place, be offered to the biggest sinners.“Begin,” says He, “ at Jerusalem”.
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.