Come December in our house we get out the Christmas stuff from above the cupboard on the landing. This stuff includes a box of about 20 Christmas books of various sorts, mostly red and some green. Among them is The Atheist's Guide to Christmas a collection of short pieces on the theme that came out a few years ago. There are 43 sections arranged under Stories, Science, How To, Philosophy, Arts, Events. Contributors include Richard Dawkins, Simon Le Bon, Derren Brown, David Baddiel, Brian Cox, etc. I have now read about half the book. I'll probably read the rest next year. The contributions vary as one would expect. Curiously, much of what they say Evangelical Christians would agree with - Christmas is a pagan festival but suffused with Christian ideas. Can't we just take what we like and leave the rest? One notes a lot of ignorance and there is a genuine sadness that intelligent men and women have made a decision, usually early in life, on the slenderest of evidence, to reject the idea of God. To me it seems that they all do believe in God but find that an assertion of atheism is the best way to deal with their aversion to the idea. It's the case of people doing their best and trying to make the most of the situation. That is the way to disaster. More positively, the book reminds us that atheists are not monsters of some sort but ordinary human beings (very nice ones too some of them) like us trying to make sense of it all. Without God we are all sunk.
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.