How do we know that the righteousness by faith is true?

Romans 10:3-4 states, 'For they being ignorant of God's righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God. For Christ is the end of the law for righteousness to every one that believeth.' This passage shows that righteousness cannot be attained through adherence to the law but is obtained through faith in Christ. The doctrine of justification by faith alone is a cornerstone of Reformed theology, affirming that believers are declared righteous before God solely based on faith in Jesus Christ's redemptive work. This reliance on Christ emphasizes grace over works and provides a firm foundation for believers' assurance of salvation.