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)

2880. Nothing else seems to a person to be that person's, that is, to be properly his own, except that which flows from freedom. The reason is that all affection that exists within love constitutes his inner life itself; and when someone acts from affection he does so from his life, that is, from himself and so from what is his, that is, properly his own. In order therefore that a person may receive a heavenly proprium such as angels in heaven have, he is maintained in freedom, and by means of the freedom is introduced into it in the way described already. Anyone may see that when worshipping the Lord in freedom one seems to do so from oneself, that is, from what is properly one's own, but when worshipping under compulsion one is not doing so from oneself but from some outside influence or from some other source that forces one to do it. Thus anyone may see that worship offered in freedom is worship itself, but worship offered under compulsion is not worship at all.