Why do Christians say salvation is by grace alone?

Salvation by grace alone is a fundamental tenet of the Reformed faith, reflecting the belief that human efforts cannot contribute to our salvation. Ephesians 2:8-9 emphasizes this by stating, 'For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.' This underscores that salvation is a total work of God, initiated by His grace and received through faith in Christ. This grace is revealed through Jesus' sacrificial death, where He atoned for the sins of His people, affirming that salvation is entirely a gift rather than a reward for human diligence or morality.