But Jerusalem which is above is free, which is the mother of us all.
Note 6 at Ga 4:26: The earthly city of Jerusalem was corrupt. Its inhabitants rejected Jesus by crucifying Him, and as a whole, they had also rejected the Gospel. But the heavenly city of God (of which the earthly Jerusalem was supposed to be symbolic) was pure and free. Those who receive salvation by faith in what Christ did for them, instead of what they do for Him through the Law, are all citizens of this heavenly Jerusalem.