I hear that Friends Reunited is on its last legs overwhelmed by the social media sites that have come since it began. I must confess I have only been on it in my wife's name. My wife signed up and after she had had a little go on it I tried and found I could look up my old schools using her log in. I felt reluctant to put my onw name put there. I'm not the only one. A friend told me had been on there and had been disappointed to find lots of names he didn't recognise. He also said that he had gone on there using an alias. Not the only one I guess! Your school days may take up only a small portion of your life but how fascinating it is to think where all the kids you once knew may be now.
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.