John Chrysostom (c. 347–407) was Archbishop of Constantinople and an important Early Church Father. He is known for his preaching and public speaking, his denunciation of abuse of authority by both ecclesiastical and political leaders, the Divine Liturgy of St John Chrysostom, and his ascetic sensibilities. The epithet "golden-mouthed" was given on account of his legendary eloquence. The Orthodox and Eastern Catholic Churches honour him as a saint and count him among the Three Holy Hierarchs (with Basil the Great and Gregory Nazianzus). He is recognised by the Eastern Orthodox Church and the Catholic Church as a saint and a Doctor of the Church. The Coptic Orthodox Church of Alexandria also recognises him as a saint. Earl Blackburn has done a very helpful biography in the Bitesize series.
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.