How do we know that God's plan of salvation is unchanging?

The doctrine of God's unchanging plan of salvation is rooted in the understanding that He is immutable — His nature and purposes do not shift with circumstances. Throughout the Bible, from Genesis to Revelation, we see a consistent theme of salvation by grace through faith. Romans 8 and Ephesians 1 highlight that before the foundation of the world, God predestined His elect for salvation through Jesus Christ. This continuity affirms that salvation has always been God’s work, entirely based on the merit of Christ and not on human decisions or efforts.