I have just finished Bruce Ware's Book The man Christ Jesus. By taking up this one aspect of Christology there is always the danger of imbalance but a book on the subject is probably needed. The teaching is quite basic really but is set out well and does help one to think through some of the issues. I won't say more as this is the book that will be discussed next at the Theological Study Group of the John Owen Centre, which meets June 16. I hope to be there. There's time to read the book and plan to join us may be, even if you weren't planning to before. The book is not long, just eight chapters.
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.