This is one of the last things I got to see before leaving Minsk today. The building was opened in 2006. As you all know, the main feature is called a rhombicuboctahedron shape. You can read more here. Sadly we did not have time to go up to the observation platform for a panoramic view of Minsk, which is an impressive city with wide main boulevrads and attractive buildings from various periods.
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.