What does the Bible say about the difference between Mount Sinai and Mount Zion?

In Hebrews 12:18-24, the author illustrates a stark contrast between Mount Sinai and Mount Zion. Mount Sinai is depicted as a place of fear and judgment, engulfed in darkness, fire, and tempest, highlighting the terrifying nature of the law that could not offer hope but condemned those who sought to obey it. In contrast, Mount Zion symbolizes the city of the living God—Heavenly Jerusalem. This mountain represents grace, joy, and fellowship with God, where believers are included in the assembly of firstborns and are assured of their communion with God through Jesus Christ, the mediator of the new covenant. The passage emphasizes the shift from bondage under the law to the freedom and acceptance believers find in Christ.