What does Scripture say about the assurance of salvation?

The assurance of salvation is a cornerstone of Reformed theology, grounded in the understanding that salvation comes through faith in Christ and His righteousness alone. As expressed in Isaiah 47, the Lord's people are reminded of their Redeemer, reinforcing that their salvation is secure in Him. This is echoed in the New Testament, where passages like Romans 8:1 affirm that there is no condemnation for those who are in Christ Jesus. The grace of God, which bestows unmerited favor upon believers, guarantees their eternal security and enables them to rest in His promises.