An item on the BBC news this morning said that scientists have recently found that eyelashes on animals all appear to conform to the same ratio (a third of the width of the eye). They didn't suggest it was due to their being designed that way but it make you wonder, eh? (If you have an open mind that is). More here.
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.