The new book by Garry Williams on the love of God, His love endures forever is a great read. Its twelve chapters are characterised not only by an unsurprising theologicality but also by a good deal of devotion, very important for such a subject (each chapter ends with a meditation of varying length and a short prayer - rather Anglican then but okay). Garry also has a nice way with his illustrations and supporting stories, some covering several pages. Not an academic book there are plenty of footnotes and a measured tone. The burden of the book is that we understand God's love as it is set out for us in God's Word rather than in terms of any merely human understanding. Few people will find it difficult to read and it is commended to all and sundry as an excellent opportunity to immerse oneself in what is a central and vital doctrine. The bibliography at the end is also useful. I thought the chapter on The love of an ever-present Father was particularly well handled.
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.