Luther’s “discovery” of the doctrine of justification is important in part because he was soul in crisis. He knew the guilt of his sins. In studying Scripture, Luther discovered the truth that salvation was not based on his good works. Instead, salvation was a matter of God declaring us righteous through Jesus Christ’s grace. If we would be right in the sight of God, we must trust in Christ alone, who took our curse away at the cross.
The goal of these words are headed into verse 23: if indeed you continue in the faith, stable and steadfast. Paul’s goal is in part to strengthen their faith and commitment to Christ. It is also to reaffirm for them that Christ’s work applies to them especially. So this is what I want you to see: We must remain committed to Christ because of what he has done for us.