How do we know grace alone means salvation is a gift?

The concept of grace alone asserts that salvation is a gift, not something we achieve through our actions or abilities. This is evident in Ephesians 2:8-9 where it states that salvation is by grace through faith and not by works. Grace signifies the unmerited favor of God, meaning we cannot do anything to deserve it or earn it. This aligns with the theological understanding that since all have sinned and fall short of God's glory (Romans 3:23), our only hope lies in God's gracious act of saving us through Christ. Thus, grace embodies the heart of the gospel, which teaches that our salvation is rooted in God's mercy and love, devoid of any human contribution.