From the mountain "burning with fire" to "the city of the living God" - Hebrews 12:18-24

When Moses approached the presence of God on Mt. Sinai he did so "trembling with fear".  The people of Israel were unable to endure the sight of Moses when he returned because he face shown with the radiance of God's glory.  Fast forward about 1500 years to the Temple in Jerusalem.  A massive curtain separates the Holy Place from the Holy of Holies.  What does this all mean?  God's people still do not have access to the glory of his presence.  Their sin prevents them from enduring the holiness of God (God's perfection cannot be in the presence of such inperfection).  Only the High Priest can enter this inner room, and only once a year (The Day of Atonement, Yom Kippur), and that only with a blood sacrifice for his own sins.
That very curtain, the symbolic separation between God and man, is torn in two at the moment of the resurrection of Jesus Christ.  The blood guilt has been paid, God's presence can now be approached by man through faith.
And so Hebrews tells us that we now approach Mount Zion, "the heavenly Jerusalem, the city of the living God" where thousands of angels rejoice and celebrate with the "spirits of righteous men made perfect".  Here Jesus "the mediator of the new covenant" awaits us with open arms.
A far cry from a gloomy mountain covered in darkness, fire, and storm isn't it?