Why is the distinction of grace alone important for Christians?

The doctrine of grace alone underscores that salvation is entirely the work of God, unenhanced by human merit. Paul addresses this by refuting the Judaizers' claims of a gospel that includes elements of the law. In Galatians 5:4, Paul states that if one accepts circumcision, they fall away from grace. It is because grace alone signifies that our acceptance before God is secured by Christ’s righteousness, not our own. Therefore, the significance lies in knowing that believers are justified and secure solely through the grace given by God, fostering true rest and assurance in Christ.