How do we know justification by faith alone is true?

Justification by faith alone is a cornerstone of Reformed theology, particularly communicated in Romans 5:1, which states, 'Therefore, being justified by faith, we have peace with God through our Lord Jesus Christ.' This doctrine maintains that faith, not works, is the means by which believers are declared righteous before God. In Romans, Paul meticulously outlines how all have sinned and need grace, demonstrating that no human effort can achieve righteousness. Faith appropriates the righteousness of Christ, ensuring that salvation is solely a work of grace, which reassures us that our standing before God is not contingent upon our imperfect actions but rests entirely on Christ's perfect obedience.