Mt. Zion is a picture of the power of God over his creatures and the wrath of God against sinners. Mt. Sinai was the place to which God came to give the Law. But God did not remain there. Mt. Zion represents the gospel and God’s eternal dwelling.
Both Mt. Sinai and Mt. Zion say something to us concerning our relationship to God and the kingdom to which we belong. Mt. Sinai speaks of Israel as God’s covenant people. It is a picture of what God would do on Mt. Zion through Jesus Christ.
Mount Sinai—The Fear of the Law
The God of Sinai is truly a God to be feared, a God of judgment and of punishment. Sinai, representing the Old Covenant, was a mountain of fear and of judgment. The writer of Hebrews is saying to his readers, "If you go back to Judaism, you are going back to a covenant of law, fear, judgment, and death." Paul described it as "the ministry of death, in letters engraved on stones" (2 Cor. 3:7).
To stand at the foot of Sinai, even without touching it, is to stand under judgment and doom. It demands and it punishes. Since no man in himself can fulfill its demands, no man in himself can escape its punishment. At Sinai, sinful and unforgiven man stands before an infinitely holy and perfectly just God. Guilty, vile, and undeserving of forgiveness, he has nothing to expect from Sinai but God's condemnation. The symbols of Sinai are darkness, fire, trembling, and trumpets of judgment. For an unforgiven sinner, "It is a terrifying thing to fall into the hands of the living God" (Heb. 10:31). There is good reason to fear at the foot of Sinai.
Mount Zion—The Grace of the Gospel
Whereas Sinai was forbidding and terrifying, Zion is inviting and gracious Sinai is closed to all, because no one is able to please God on Sinai's terms—perfect fulfillment of the law. Zion is open to all, because Jesus Christ has met those terms and will stand in the place of anyone who will come to God through Him. Zion symbolizes the approachable God.
Sinai was covered by clouds and darkness; Zion is the city of light. "Out of Zion, the perfection of beauty, God has shone forth" (Ps. 50:2). Sinai stands for judgment and death; Zion for forgiveness and life, "for there the Lord commanded the blessing—life forever" (Ps. 133:3).
In coming to Mount Zion—that is, by becoming a Christian—we come to seven other blessings: the heavenly city; the general assembly; the church of the first-born; God, the Judge of all; the spirits of righteous men made perfect; to Jesus; and to the sprinkled blood.
For every man the choice is the same. Whether we are Jew or Gentile, to try to approach God by our works is to come to Sinai and to discover that our works fall short and cannot save us. Whether we are Jew or Gentile, to trust in the atoning blood of Jesus Christ is to come to Zion, where our heavenly High Priest will mediate for us and bring us to the Father, and where we find reconciliation, peace, and eternal life. And if you have truly come to Zion and received all its blessings, it is inconceivable that you would want to hold on to Sinai in any way.
In a day of Praise songs and Praise teams, I will sound very old and antiquated to say we used to sing the hymn, “We’re Marching to Zion.” There was something encouraging and refreshing to hear the saints repeat the words, “We’re marching to Zion, beautiful beautiful Zion, We’re marching upward to Zion, that beautiful city of God.” As imperfect as God’s people may be in this age, we are still citizens of heaven. We no longer live under the fear and condemnation of God’s law. We reverentially serve our Lord under the banner of the cross with our eyes fixed toward “…mount Zion, and unto the city of the living God.”