Why is Christ's substitutionary work important for believers?

The substitutionary work of Christ is cornerstone to the doctrine of grace. The preacher emphasizes that everything God requires from His people, He has provided through Jesus Christ. When Christ fulfilled the law perfectly and paid the penalty for sin, He did so on behalf of His elect. This means that for those who are in Christ, God does not see their sin but rather the perfect righteousness of His Son. This assurance that we are now seen as perfect before God removes the burden of trying to earn acceptance through our own service or good works. Instead, our works should flow from gratitude for what He has already accomplished for us, allowing us to serve freely out of love rather than obligation or fear.