What does the Bible say about defending the gospel?

In the context of Galatians 2, the Apostle Paul underscores the necessity of defending the gospel when confronted with false brothers who sought to impose a works-based righteousness through the law. He asserts that he did not yield to these pressures in order to ensure that the truth of the gospel remained intact for the Galatian believers. Paul distinguishes between the true gospel of grace and the distorted version proposed by the Judaizers, emphasizing that any gradual addition to the gospel is detrimental to its core message of salvation by grace alone through faith alone in Christ alone.