I went to the funeral of a neighbour today. It appears that he gave his life to Christ in the final week of life. Bavinck says that Arminians or Remonstrants attach little value to a deathbed conversion. When people have spent their whole lives “in sin” and have turned a deaf ear to all the invitations and warnings of the gospel, they consider such a last-minute conversion, which can no longer be proved by a new life, highly improbable, indeed impossible other than by an extraordinary act of divine mercy (Episcopius, P van Limborch) The Walloon preachers Jacques Bernard and Pierre Joncourt later expressed the same judgement. But on this subject, the Reformed generally held a more charitable opinion (C. Vitringa, Doctr. christ., III, 100–104).
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.