Obedience to the Law apart from faith does not justify, but those who have been justified will necessarily produce fruit worthy of the Holy Spirit, repentance, and justification.
“[W]hen obedience happens in those who have been justified, it merits other great rewards. [However] God puts His saints to work in various ways, and often holds back the rewards of works-righteousness. He does this so that they may learn not to trust in their own righteousness, and may learn to seek God’s will rather than the rewards. This can be seen with Job, Christ, and other saints.”
— Book of Concord; “Apology of the Augsburg Confession:”
Love and Fulfilling the Law, paragraphs 76-77. Emphasis added.