What is the significance of God's immutable purpose?

God's immutable purpose is significant because it assures believers that all of His promises will be fulfilled without alteration or failure. The sermon emphasizes that God's plans are not tentative or subject to change; they are firmly established in eternity. This provides a strong foundation for faith and hope, as believers can trust that God will accomplish all that He has promised. As noted in Ephesians 3:20, God is able to do far more abundantly than we can ask or think, reinforcing the idea that His purposes extend beyond human comprehension.