I've recently read Mike Reeves two Paternoster books The good God and Christ our life. I read the first (which is subtitled, on Father, Son and Spirit) on my kindle and the second in traditional format. Both books are written in a racy but highly theological style that makes good use of past masters. The books are illustrated throughout and certain sections are placed in separate panels, which all adds to the delight of the experience. These books have now been published in America by IVP as Delighting in the Trinity and Rejoicing in Christ. Not everyone copes so well with this fresh approach but it is good to know that a fresh voice is articulating ancient truth in the modern vernacular.
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.