Paul in this chapter continues to show the Galatians they were no longer under the Law. Paul takes the story of Abraham and compares Abraham’s two sons to the two covenants. What is interesting is that Paul also connects the physical city of Jerusalem to the old Law and thus the importance of the city of Jerusalem will fade also with the coming of the new covenant! When Jerusalem and the temple were destroyed in 70 AD – it marked the end of the old covenant, earthly Zion, and the temple. So when scripture talks of the glorification of Jerusalem and the temple as part of the new covenant – it is not talking about the physical city of Jerusalem, but spiritual Jerusalem! Many miss this point when reading O.T. prophecies and thus they are looking for Jesus to reign in the future in the physical city of Jerusalem. For all those that obeyed the gospel are citizens in spiritual Israel!