What does the Bible say about the eternal covenant and Christ's work?

According to the Scriptures, Christ's coming into the world was purposed by the Father, who established an eternal covenant to redeem a specific people. This covenant outlines God's sovereign grace and highlights Christ as the mediator through whom this redemption is executed. Isaiah’s prophecies and New Testament affirmations demonstrate that Christ embodies the fullness of God's plan. His role in salvation serves not only to fulfill the covenant but also underscores the importance of God's sovereign choice in salvation, affirming that His government and peace shall endure forever.