The "midst" of something in the Bible represents the thing that is most central and most important to the spiritual state being described, the motivation that drives everything else. In general this will be something we love or feel, because at the core of things we are what we love; our loves define us.

(References: Apocalypse Revealed 44, 90, 268; Arcana Coelestia 2252, 2940, 10153, 10365, 10557, 10635, 10641)

9357. It should be recognized that the Word on our planet, given to us by the Lord by way of heaven, constitutes a union of heaven and the world, 9212. To this end there is a correspondence of everything in the letter of the Word with Divine realities in heaven. It should also be recognized that the Word deals in its highest and inmost sense with the Lord, with His kingdom in heaven and on earth, and with love and faith received from Him and shown to Him, consequently with life received from Him and abiding in Him. Such ideas present themselves to angels in heaven, whatever planet they come from, when the Word existing on our planet is read and preached.