How do we know that salvation cannot be earned by obedience to the law?

Salvation cannot be earned through adherence to the law because it rests solely on the grace of God. The Scriptures repeatedly affirm that no one can achieve righteousness through their works, as all have sinned and fall short of the glory of God (Romans 3:23). The promise of salvation through faith in Christ, not by works, underlines this point. Ephesians 2:8-9 explicitly states that it is by grace we are saved, not by works, so that no one can boast. This underscores the sovereign grace theology that we are entirely reliant on God’s mercy and not our merits.