How do we know that the doctrine of salvation by grace alone is true?

The doctrine of salvation by grace alone is firmly established in Scripture, particularly in the writings of the Apostle Paul. The emphasis on Christ's redemptive work in passages like Galatians 1:4 highlights that salvation hinges not on human effort but solely on God's sovereign grace. This principle of grace is foundational to the historic Reformed theology, affirming that no amount of human effort can contribute to our salvation. Instead, it is Christ’s complete and finished work that secures our redemption, and this is evidenced by the consistent theme of grace throughout the New Testament, where it is made clear that salvation is a gift from God.