Question: "What is Zion? What is Mount Zion? What is the biblical meaning of Zion?"
Answer: Psalm 87:2-3 says, “The LORD loves the gates of Zion more than all the dwellings of Jacob. Glorious things are said of you, O city of God.” Occurring over 150 times in the Bible, the word “Zion” essentially means “fortification.” In the Bible, Zion is both the city of David and the city of God. As the Bible progresses, the word “Zion” transitions from referring primarily to a physical city to having a more spiritual meaning.
The first mention of the word “Zion” in the Bible is 2 Samuel 5:7: “Nevertheless, David captured the fortress of Zion, the City of David.” “Zion,” therefore, was originally the name of the ancient Jebusite fortress in the city of Jerusalem. “Zion” came to stand not only for the fortress but also for city in which the fortress stood. After David captured “the stronghold of Zion,” Zion was then called “the City of David” (1 Kings 8:1; 1 Chronicles 11:5; 2 Chronicles 5:2).
When Solomon built the temple in Jerusalem, “Zion” expanded in meaning to include the temple and the area surrounding it (Psalms 2:6; 48:2, 11-12; 132:13). “Zion” was eventually used as a name for the city of Jerusalem, the land of Judah, and the people of Israel as a whole (Isaiah 40:9; Jeremiah 31:12; Zechariah 9:13).
The most important use of the word “Zion” is in a theological sense. “Zion” is used figuratively of Israel as the people of God (Isaiah 60:14). The spiritual meaning of “Zion” is continued in the New Testament, where it is given the Christian meaning of God's spiritual kingdom, the heavenly Jerusalem (Hebrews 12:22; Revelation 14:1). Peter refers to Christ as the Cornerstone of Zion: “See, I lay a stone in Zion, a chosen and precious cornerstone, and the one who trusts in Him will never be put to shame” (1 Peter 2:6).