We read Genesis 35 yesterday including verse 4 So they gave Jacob all the foreign gods they had and the rings in their ears, and Jacob buried them under the oak at Shechem. You wonder what the problem was with gold earrings but then may be the earrings were on the idols (as above).
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.