Justice demands “the unfailing consequence of blessings for righteous thoughts and acts, and punishment for unrepented sin. Justice is an eternal law that requires a penalty each time a law of God is broken (Alma 42:13–24). The sinner must pay the penalty if he does not repent (Mosiah 2:38–39; D&C 19:17). If he does repent, the Savior pays the penalty through the Atonement, invoking mercy (Alma 34:16)” (Guide to the Scriptures).