How do we know that eternal life is through grace alone?

Scripture clearly teaches that eternal life is a gift that cannot be earned through works but is given through God's unmerited favor, which we access by faith. Romans 6:23 states that the wages of sin is death, but the gift of God is eternal life through Jesus Christ our Lord. Ephesians 2:8-9 further clarifies that by grace we have been saved through faith, and not of ourselves; it is the gift of God, not of works, lest anyone should boast. This affirmation roots the Christian faith in grace, affirming that salvation and eternal life depend solely on Christ's completed work on the cross.