Galatians 4:9, 10, 21-24, 26-28

So now that you know God (or should I say, now that God knows you), why do you want to go back again and become slaves once more to the weak and useless spiritual principles of this world? You are trying to earn favor with God by observing certain days or months or seasons or years. Tell me, you who want to live under the law, do you know what the law actually says? The Scriptures say that Abraham had two sons, one from his slave wife and one from his freeborn wife. The son of the slave wife was born in a human attempt to bring about the fulfillment of God’s promise. But the son of the freeborn wife was born as God’s own fulfillment of his promise. These two women serve as an illustration of God’s two covenants. The first woman, Hagar, represents Mount Sinai where people received the law that enslaved them. But the other woman, Sarah, represents the heavenly Jerusalem. She is the free woman, and she is our mother. As Isaiah said, “Rejoice, O childless woman, you who have never given birth! Break into a joyful shout, you who have never been in labor! For the desolate woman now has more children than the woman who lives with her husband!” And you, dear brothers and sisters, are children of the promise, just like Isaac. (Galatians 4:9, 10, 21-24, 26-28 NLT)