There are two mountains in the Bible that symbolize the kingdom of God: Mount Sinai and Mount Zion. In the book of Galatians, Paul testified to Mount Sinai and Mount Zion, with Mount Sinai testifying to physical Israel under the Old Testament law and Mount Zion testifying to spiritual Israel under the New Testament. So what is the difference between the two? Mount Sinai was called the Mountain of God because it was the first place God made his home.

[Exodus 3:1] Now Moses kept the flock of Jethro his father in law, the priest of Midian: and he led the flock to the backside of the desert, and came to the mountain of God, even to Horeb.

Thus, the Israelites of the Old Testament thought of God's mountain as Mount Sinai, but God swore to David that He would move His dwelling place from Mount Sinai to Mount Zion, where Jerusalem is.

[Psalms 132:11~14] The LORD hath sworn in truth unto David; he will not turn from it; Of the fruit of thy body will I set upon thy throne. If thy children will keep my covenant and my testimony that I shall teach them, their children shall also sit upon thy throne for evermore. For the LORD hath chosen Zion; he hath desired it for his habitation. This is my rest for ever: here will I dwell; for I have desired it.

Thus, the dwelling place of God was moved from Mount Sinai to Mount Zion, but when Solomon, David's son, worshiped pagan gods, God vacated the dwelling place on Mount Zion and returned to Mount Sinai.

[1 Kings 19:8] So he got up and ate and drank. Strengthened by that food, he traveled forty days and forty nights until he reached Horeb, the mountain of God. There he went into a cave and spent the night. And the word of the LORD came to him: "What are you doing here, Elijah?"

So what does all this history mean? As Paul testified, Mount Sinai symbolized physical Israel, which kept the Old Testament laws, and Mount Zion symbolized spiritual Israel. When God moved His dwelling place from Mount Sinai to Mount Zion, He was showing that His blessings on physical Israel would be transferred to spiritual Israel. But when David's son Solomon turned to idolatry, God left Mount Zion and went back to Mount Sinai, showing that God's Holy Spirit would leave the early church, which fulfilled Solomon's prophecy, when it followed heretical doctrines. But as God swore to David, Mount Zion will appear high above the world.

[Revelation 14:1] Then I looked, and there before me was the Lamb, standing on Mount Zion, and with him 144,000 who had his name and his Father's name written on their foreheads.

Thus, Mount Zion, where the oath was sworn to David, symbolizes the spiritual Israel of the New Testament, while Mount Sinai symbolizes the physical Israel.

[Revelation 14:1] Then I looked, and there before me was the Lamb, standing on Mount Zion, and with him 144,000 who had his name and his Father's name written on their foreheads.

Therefore, Mount Zion, which he swore to David, was a symbol of spiritual Israel in the New Testament era. Mount Sinai is on earth, but Mount Zion is in heaven. Physical Israel received the Ten Commandments covenant on Mount Sinai, and spiritual Israel received the Holy Spirit on Mount Zion in heaven. Therefore, if you study the history of Zion (temple) well, you will see the history of spiritual Israel starting with Yehoshua. More information on this can be found at the link below.

http://godnara.egreef.kr/bbs/board.php?bo_table=cs_notice_eng&wr_id=166&page=3