How do we know the doctrine of justification by faith alone is true?

Paul's letters, especially to the Galatians, vehemently emphasize that justification comes through faith alone and not through the law. In Galatians 2:16, Paul declares, 'A person is not justified by the works of the law, but by faith in Jesus Christ.' This doctrine is further supported by Romans 3:28, which states, 'For we hold that one is justified by faith apart from works of the law.' This principle is fundamental to Reformed theology, affirming that salvation is entirely God's work, initiated and completed by Him through Christ, and is received only by faith. The sufficiency of Christ's atonement completely eliminates the need for any works to secure our justification.