What does Galatians 3:15–25 reveal about what God does in my place and on my behalf (Son)?
Jesus Christ came to obey God’s law perfectly in my place and die the death that I deserve for my sin. He came to fulfil God’s law, thereby bringing the time of the old covenant to an end. Through faith in him, his death is considered my death (punishment for my sin) and his life of perfect righteousness is imputed to me (as if it is my life of perfect righteousness).
15 To give a human example, brothers: even with a man-made covenant, no one annuls it or adds to it once it has been ratified.