How do we know that salvation is by grace through faith and not works?

The doctrine of salvation by grace is central to Reformed theology, firmly established in Ephesians 2:8-9, which affirms that we are saved by grace through faith, not of works, lest anyone should boast. Furthermore, Romans 3:20 states that no flesh will be justified by the works of the law. Our righteousness before God comes solely through faith in Christ's completed work, not through our attempts at law-keeping or personal merit. This truth emphasizes God's sovereign grace, as it assures us that our salvation is entirely dependent upon His initiative and grace rather than our ability to perform.