This should come as no surprise to anyone, but one of Jimmy Needham's songs got to me today. It's called "Moving to Zion" (http://www.newreleasetuesday.com/lyricsdetail.php?lyrics_id=62499) and it is a depiction of the shift from living as though on Mount Sinai to living as though on Mount Zion.
Sinai was the place (literally) where Moses was given the law on the tablets that were eventually placed in the Ark of the Covenant. It was a place where only he was allowed to go because He would be in the presence of God...the Israelites were not granted direct access to God and they were under strict instructions to not even touch the mountain for the 40 days that Moses was there. From this time on, God's glory resided in the Ark of the Covenant in the Tabernacle...and it led the Israelites where they were to go, in the form of a cloud by day and a pillar of fire at night. To sum it up, Sinai was the place where God demonstrated His holiness and supremacy.
Zion is the place (figuratively) where God currently displays His glory. Not His physical glory, of course, because we won't witness that until we are in Heaven, but the glory that is available to us while we are on this temporal earth...this is the glory that we are called to demonstrate to the world. He has sent His Spirit to reside in us, so that we can bring Him glory and honor for as long as we live. We have direct access to our Lord because Jesus died to save us from the punishment of our sins and so that the Advocate could come down to us at Pentecost. To sum up, Zion is the place where God demonstrated and continues to demonstrate His grace and His desire to have a personal relationship with us. And this Zion in which we are currently residing is just a taste of the true Zion that we will experience in Heaven one day.
"You have not come to a physical mountain, to a place of flaming fire, darkness, gloom, and whirlwind, as the Israelites did at Mount Sinai...No, you have come to Mount Zion, to the city of the living God, the heavenly Jerusalem, and to countless thousands of angels in a joyful gathering." --Hebrews 12:18, 22
"God's law was given so that all people could see how sinful they were. But as people sinned more and more, God's wonderful grace became more abundant." --Romans 5:20
"Sin is no longer your master, for you no longer live under the requirement of the law. Instead, you live under the freedom of God's grace." --Romans 6:14
"If the law could give us new life, we could be made right with God by obeying it. But since the Scriptures declare that we are all prisoners of sin, so we receive God's promise of freedom only by believing in Jesus Christ." --Galatians 3:21b-22
And then Paul (well God through Paul) gives us this illustration:
"Tell me, you who want to live under the law, do you know what the law actually says? The Scriptures say that Abraham had two sons, one from his slave wife and one from his freeborn wife. The son of the slave wife was born in a human attempt to bring about the fulfillment of God's promise. But the son of the freeborn wife was born as God's own fulfillment of His promise.
These two women serve as an illustration of God's two covenants. The first woman, Hagar, represents Mount Sinai where people received the law that enslaved them. And now Jerusalem is just like Mount Sinai in Arabia, because she and her children live in slavery to the law. But the other woman, Sarah, represents the heavenly Jerusalem. She is the free woman and she is our mother...And you, dear brothers and sisters, are children of the promise, just like Isaac." --Galatians 4:21-28