It's good to get back to a bit of Dr Lloyd-Jones every now and again. True Happiness contains four lightly edited sermons (they have been put into book form but are clearly sermons and might have been better for being left more as such) preached in January of, well, it doesn't say what year. That info is not available at the site where the sermons can be heard either (see here). It would be nice to know. I am assuming these were evening sermons as they are pretty evangelistic. More homiletic then exegetical they are very helpful. This 110 page edition is produced by CFP and Bryntirion together and is uniform with other volumes on Psalms 51, 73 and 107. There is a foreword by Tulliam Tchividjian (lost on me but worth having in there if it connects with a younger generation). Worth checking out.
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.