Why is God's immutability crucial for salvation?

The immutability of God is essential to the doctrine of salvation because it guarantees the reliability of His promises. Hebrews 6:18 highlights that 'it is impossible for God to lie.' This means that the promises God makes regarding salvation are not wishful thinking; they are absolute realities grounded in His unchanging character. Believers can have full assurance that once they are saved, they cannot lose that salvation because God does not change His mind. This gives us a deep sense of security and peace, knowing that our standing before God is not dependent on our actions, which can fluctuate, but on God's unchanging promise and purpose in Christ. Thus, His immutability is a stronghold for believers in their salvation journey.