How did surnames begin? Hereditary surnames were unknown among the Anglo-Saxons. It was not until the twelfth century that these came into use, and not universally even then. Many of them were formed by adding son to the father's Christian name, such as Johnson, Ferguson, and so on. Others sprang from localities as Attwood, Byfield, Green, Abbey, Townsend, who were domiciled respectively at or by the wood, field, green, abbey and town's end. More important people took the name of the village or township in which they lived, for example John of Derby would later be plain John Derby. A very large class ofsurnamess recall the occupations of their original owners, as Smith, Miller, Baker, Tanner, Fuller, Mason, Dyer, Abbott; while a vast number arose from nicknames and epithets (not always complimentary) given to their original bearers on account of their personal appearance or characteristics. A few taken at random are Hogge, Fox, Short, Swift, Longman, Rich isself explanatory; but not to Power; which means the exact opposite and was originally poor. Not all English surnames are English in origin. Russell for example is Anglo French and means red haired.
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.