Our natural instinct is to try to earn righteousness, but the only way is to receive it as a gift from God. The offer is made of complete righteousness in Jesus, and only in him.
1. A reminder of the birth of Abraham's two sons, one by the slave woman, Hagar, one by Abraham's wife. Hagar = law, Sarah = promise.
2. Those who trust in Christ are free:
a. Free from burden of the Law.
b. Free to keep the Law in love. We remain sinners though.
We should stand firm in Christ. We find it hard to believe in God's free gift and keep trying to earn righteousness.