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.

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

903. And on them the names of the twelve apostles of the Lamb. This symbolizes all of the doctrines from the Word regarding the Lord and living in accordance with His commandments.

The foundations had the names of the twelve apostles of the Lamb written on them because the twelve apostles symbolize the Lord's church and everything connected with it (nos. 79, 233, 790), in this case the church in respect to all of its doctrines, because their names were written on the twelve foundations, which symbolize all of the doctrines of the New Jerusalem (no. 902). The twelve names symbolize its whole character, and its whole character has to do with two elements in the doctrine and so in that church: the Lord and living in accordance with His commandments. Therefore these are what are symbolized.

All of the doctrines of the New Jerusalem relate to these two elements, because they are its universal tenets on which all of its particular ones depend, and they are the essential elements from which all of its outward expressions originate. Therefore they are, as it were, the soul and life in all of its doctrines.

They are, indeed, two elements, but one cannot be divorced from the other. For to divorce them would be like divorcing the Lord from mankind, or mankind from the Lord, and in that case there would be no church.

These two elements are joined together like the two tables of the Ten Commandments, one of which contains commandments having to do with the Lord, and the other commandments having to do with people. There they are called a covenant, and a covenant symbolizes conjunction.

Think what the case would be with the tables of the Ten Commandments if only the first were to remain and the second were to be snatched away. Or if the second were to remain and the first were to be snatched away. Would it not be as though God did not see mankind, or as though mankind did not see God? Or as though one abandoned the other?

We say this to make it known that everything connected with the doctrine of the New Jerusalem relates to love toward the Lord and love for the neighbor. To love the Lord is to have faith in the Lord and obey His commandments, and to obey His commandments is to love the neighbor, since to obey the Lord's commandments is to be of useful service to the neighbor. People who love the Lord are those who obey His commandments, as the Lord Himself teaches in John 14:21-24. And love toward the Lord and love for the neighbor are the two commandments on which hang the Law and the Prophets (Matthew 22:37-40). The Law and the Prophets mean the Word in its entirety.