We were back to full strength last Wednesday and we had a visitor too who is thinking of joining us in the near futre. Encouraging. Before we prayed we looked again at Leviticus 23 and at the Spring festivals in ancient Israel - Passover and Pentecost, basically. It was good to bring the New Testament data to bear on these verses. I am sorry I don't have a clearer grasp of the Jewish feasts. Hopefully this run through Leviticus 23 will help.
The similar phrase 'Worldly Christianity' is one used by Bonhoeffer. 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.