Justification is God’s sovereign, once-for-all legal act, granted by grace through faith, in which sinners rest on Christ’s atonement rather than any merit of their own. But justification does not change us morally in itself; Christ’s righteousness then begins to bear fruit through an ongoing process of change, and that process is sanctification.
Because we serve the Holy One who called us, we are to “be holy… in all our behavior, because it is written, You shall be holy, for I am holy.” The sermon calls believers to see sanctification as the fruit of justification, not earning God’s favor, but increasingly reflecting the holiness of the God who has already saved them.