How do we know that grace is the means of salvation?

Salvation by grace is a core doctrine of the Christian faith, highlighted in Ephesians 2:8-9, which states, 'For by grace are you saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast.' This emphasizes that salvation is not something we can earn or achieve through good works but is a result of God's unmerited favor towards us. God's grace is His initiative in saving sinners, reflected in His sending of Jesus Christ to atone for sin. The power of salvation is not in human efforts but entirely in the sovereign grace of God.