How do we know that Paul's teachings in Romans are true?

Paul's teachings in Romans are rooted in the truth of the Gospel, which states that salvation is entirely of grace and not through works. The doctrinal truths that Paul lays out about sin, justification, and sanctification resonate with the beliefs and experiences of believers throughout history. The obedience of the Roman believers referenced in Romans 16:19 is a testament to the effectiveness of God's Word in their lives. Their transformation serves as a practical verification of the teachings found in this epistle.