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.

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

10153. 'And I will dwell in the midst of the children of Israel' means the Lord's presence and His influx through good in heaven and in the Church. This is clear from the meaning of 'dwelling', when this is said of the Lord, as His being present and flowing in, His doing so through Divine Good being meant because 'dwelling' has reference to good, see 2268, 2451, 2712, 3613, 8269, 8309, which is why the words 'in the midst' are used, because 'the midst' means what is inmost, and that which is inmost is good (for this meaning of 'the midst', see 2940, 2973, 5897, 6084, 6103); and from the representation of 'the children of Israel' as the Church, dealt with in 9340.

[2] The reason why 'dwelling in the midst', when said of the Lord, means His presence and influx through Divine Good is that the Lord flows into and is present with a person in the good he receives from the Lord. Good composes the person's true self, for everyone's character is conditioned by his good. By good, love should be understood, since anything that is loved is called good. The fact that a person's love or good makes him what he is may be recognized by anyone at all who observes what another is like; for having observed him he can direct him by means of his love wherever he wishes him to go, so much so that when that other person is held under the sway of his own love he is no longer his own master, and reasons which disagree with his love count for nothing with him, while those which collude with his love count for everything.

[3] The truth of this is also plainly evident in the next life. All spirits there are recognized by their loves, and when they are held under the sway of those loves they cannot act in any way contrary to them; for if they act contrary to those loves they act contrary to themselves. They are therefore embodiments of their loves, those in the heavens being embodiments of heavenly love and charity, so beautiful that they are beyond description, whereas those in the hells are embodiments of their own loves, namely self-love and love of the world, and are consequently embodiments also of hatred and vengeance, thus are monsters so awful that they defy description.

[4] Since therefore a person's love makes him altogether what he is, it is evident that the Lord cannot be present in a person's love if it is evil, only in a person's love that is good, thus in his good. People think that the Lord is present in truth called the truth of faith; but He is not present in truth devoid of good. Where good exists however He is present in truth through that good; and He is present in truth to the extent that it leads to good and to the extent that it emanates from good. Truth devoid of good cannot be said to be within a person; it is merely in his memory, residing there as factual knowledge which does not enter the person and form part of him until it becomes part of his life. It becomes part of his life when he loves it, and in love lives in accord with it. When this happens the Lord dwells with him, as also the Lord teaches in John,

He who has My commandments and does them, he it is who loves Me, and I will love him and will manifest Myself to him. And My Father will love him, and We will come to him and make Our home with him. John 14:21, 23.

'Manifesting Himself' means enlightening with the truths of faith from the Word; 'coming to him' means being present; and 'making Their home with him' means dwelling in his good.