How do we know God gets all the glory in justification?

Justification is a declaration of righteousness made by God on behalf of His people, based solely on the completed work of Jesus Christ. In John 19:30, Christ says, 'It is finished,' signifying that all that is needed for our justification was accomplished on the cross. If human efforts were involved, then glory could be claimed by us. However, Romans 3:28 affirms that we hold that 'a man is justified by faith without the deeds of the law.' Therefore, it becomes clear that it is God's grace and His work in our lives that secures our justification, placing all glory back into His hands.