There are no two things in the Bible more different than LAW and GRACE, which is nothing more than salvation by our works or salvation by free grace through the obedience and death of our Lord Jesus. The first assignment in learning the gospel is to learn the difference between law and grace. He who learns the lesson well can call himself a theologian.
Paul calls the story of Sarah and Hagar an allegory (Gal. 4:24). An allegory is a story in which the characters are used to picture other real characters and real actions.
God promised Abraham a son by his true wife, Sarah. Time passed and no son was born; so Sarah gave her servant, Hagar, to Abraham to bear him a son. Ishmael was born to Hagar by Abraham. In due time the promised son, Isaac, was born to Sarah. The son of the servant, Hagar, mocked Isaac and proved that the two could not live together; so Hagar and Ishmael had to be put out of the household. Isaac reigned alone as the heir of Abraham.
1. Paul said that these two women represent the two covenants.
Hagar, the servant, represents the covenant of law, works, and ceremonies from Mt. Sinai. In the covenant of law and works God says, "Do this and live."
Sarah, the true wife of Abraham, represents God's eternal covenant of grace in Christ Jesus. This covenant was first, was from all eternity, was not made between God and men but between the Father, Son, and Holy Spirit (Heb. 7:22; Heb. 13:20; John 17:2-3). The covenant of grace says, "Do this, O Christ, and men shall live." God gives eternal life without works from men (Rom. 3:19-24).
2. Though Hagar bore the first son, as the covenant of works gave us fallen Adam and a depraved race, yet sarah was the original and first wife of Abraham, as the covenant of grace was the first covenant. The covenant of works was REVEALED first: but before there was ever a sinner, there was a covenant of grace and its surety, Christ Jesus. Jesus Christ was the Lamb slain before the foundation of the world (Rev. 13:8; Rev. 17:8; I Peter 1:18-21). We were chosen in Christ before the world began (Eph. 1:3-4: II Thess. 2:13).
3. Hagar was never intended to be the wife of Abraham, nor was Ishmael THAT SEED which was promised. Hagar was the handmaid of Sarah. So the law was never given nor intended to save anyone. It was only a handmaid to grace to point men to Christ, the seed (Gal. 3:21-29; Gal. 3:16). The law properly used is a blessing. It shows our sins, our inability; it shuts men up to Christ. If the law is the servant to grace, that's well and good; but when the law tries to be the master or on equal footing with grace, it must go! (Gal. 4:30-31.)
4. Hagar was never free and Sarah was never in bondage. The. covenant of works and none of her children are free. All who live by the law are under the curse (Gal. 3:10-13). But the seed of Abraham by faith are free: "for if the Son shall make you free, ye shall be free indeed."
5. Hagar must be cast out as well as her son (Heb. 10:1-10). The covenant of works has ceased, being fulfilled by Christ. It cannot have a place in the redemption and reign of Christ Jesus. Nor is he a son of Abraham who is one by flesh or natural birth. He is a son of Abraham who is one by faith in Jesus Christ (Rom. 2:28-29: Gal. 3:7-9, 16, 29).
6. As the two women are types of the two covenants, so the two sons are types of those who live under each covenant.
Ishmael is the man who trusts his works and seeks a righteousness before God bv his deeds. Isaac is the man born supernaturally of God (John 1:13), brought to faith in Christ, and walks in the Spirit, not the flesh, whose wisdom, righteousness, sanctification, and redemption is Christ (I Cor. 1:30;. Col. 2:9-10).
Ishmael is the older, as the old man is older than the new man created in Christ Jesus. We are all born flesh first, then born again with that new nature which lives forever.
Ishmael is the son of the flesh; Isaac is the son by Divine power. We are all born sons of men, then sons of God.
Ishmael's attitude toward Isaac (Gal. 3:29) is the same attitude the legalist displays toward sons of grace today. You will never find a free-will legalist to be tolerant toward the gospel of grace. The gospel of grace destroys his very foundation, which is MERIT, not MERCY!