Jerusalem, on Mount Zion, signifies the doctrine of love to the Lord, and how it governs your life. Jerusalem first comes to our attention in 2 Samuel 5, when King David takes the city from the Jebusites and makes it his capital. In the next chapter he brings the Ark of the Covenant there, and later it is where Solomon builds the temple, and his own palace. From then on Jerusalem is the center of worship of the Israelitish church. It is the place where the Lord was presented in the temple as a baby, where He tarried to talk to the priests at age twelve, where He cleansed the temple, had the last supper, was crucified and then rose. It is a central place in both the old and new Testaments. The city was built on Mount Zion, the highest point of the mountains of Judea. A city, in the Word, represents doctrine, the organized knowledge of the truths of the church. Mountains represent love of the Lord and the consequent worship. If you put those things together, Jerusalem on Mount Zion signifies the doctrine of love to the Lord, and how it governs your life. This is why David was led to make Jerusalem the most important city of the land, and why all worship was conducted there. And this is also why Jeroboam was condemned for introducing idol worship in Samaria. In the Book of Revelation, John's vision of the city New Jerusalem descending from God is a prophecy of a new dispensation of doctrine coming from the Lord.

(Verweise: Arcana Coelestia 4539, 8938; The Apocalypse Explained 365 [35-38])

366. That they should slay one another, signifies the falsification or extinction of truths. This is evident from the signification of "slaying," as meaning the extinction of truths; for "to slay" in the Word signifies to slay spiritually, that is, to slay the spiritual part of a man or his soul, which is to extinguish truths. It also means to falsify, because when truths are falsified they are also extinguished; for falsification produces a different understanding of truths, and truth is true to everyone according to his understanding of it; for the love and principle that rule in man draw and apply all things to themselves, even truths themselves; consequently when the love is evil, or the principle is false, then truths are infected with the evil of the love or the falsity of the principle, and thus are extinguished. This, therefore, is what is here signified by "they should slay one another." That this takes place when there is no good with man, and especially when there is no good in the doctrine of his church, is evident from the preceding words, where it is said, "When he had opened the second seal there went forth a red horse; and to him that sat upon him it was given to take peace from the earth;" which signifies a second state of the church when the understanding of the Word is destroyed in respect to good, which is the source of dissensions in the church (of which see above, n. 361, 364, 365).

[2] That the understanding of the Word, or what is the same, the understanding of the truth, is destroyed when there is no good with man, that is, when there is no love to the Lord and charity towards the neighbor, may be seen above n. 365; for good with man, or what is the same, love with him, is the fire of his life, and truth with him, or the faith of truth, is the light therefrom; consequently such as the good is, or such as the love is in man, such is truth, or such the faith of truth in him. From this it can be seen that when evil or an evil love is with man there can be no truth or faith of truth with him; for the light that goes forth from such fire is the light that those have who are in hell, which is a fatuous light like the light from burning coals, which light, when light from heaven flows in, is turned into mere thick darkness. Such also is the light that with the evil, when they reason against the things of the church, is called natural light [lumen].

[3] That they would falsify and thereby extinguish truths is meant also by the Lord's words in Matthew:

Jesus said to the disciples, The brother shall deliver up the brother, the father the son; children shall rise up against parents, and cause them to be put to death (Matthew 10:21).

And in Luke:

Ye shall be delivered up by parents, and brethren, and kinsfolk, and friends; and some of you shall they cause to be put to death (Luke 21:16).

"Parents," "brethren," "children," ["kinsfolk, "] and "friends," do not mean here parents, brethren, children, kinsfolk, friends, nor do "disciples" mean disciples, but the goods and truths of the church, also evils and falsities; it is also meant that evils would extinguish goods and falsities truths. (That such is the signification of these words, see Arcana Coelestia 10490.)