Paul is passionate about hammering this point in for the Galatians: we must not live as slaves, but everything should point to Christ, or else we'll burn out and get paralyzed by our own sense of worth and legalism. To really nail this message in, he drops this bomb on the Jews: keeping the Law for your salvation means Hagar is your mother, not Sarah. All followers of Christ must know that the promised legacy of Abraham and Sarah is freedom, not slavery. What are the things that you place your sense of worth in that keep you bonded in slavery and apart from God?