How do we know salvation is by grace through faith?

Ephesians 2:8-9 teaches that we are saved by grace through faith, emphasizing that this is not of ourselves but a gift from God, so that no one may boast. This highlights the necessity of recognizing our own inability to earn salvation through works. Romans 3:23-24 also lays this foundation by stating that all have sinned and fall short of the glory of God but are justified freely by His grace. Therefore, our reliance is solely on Christ's redemptive work and God’s grace, showcasing the sovereign nature of salvation where faith acts as the means through which we receive the grace already available to us in the Gospel.