Galatians 3:15-18

Order of Service

• Call to Worship — Psalm 95:1-7
• Hymn — Come, Christians, Join to Sing (#302)
• Shorter Catechism — Questions 76, 77, and 78 (Ninth Commandment)
• Hymn — 'Tis So Sweet to Trust in Jesus (#679)
• Pastoral Prayer
• Sermon
• Hymn — O Lord, Be Thou My Helper True (#50)
• Benediction — 2 Corinthians 13:14

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Sermon Title: The Details of the Covenant of Grace

Scripture: Galatians 3:15-18

I. Your Justification Is According to an Unchangeable Covenant

A. Paul argues from lesser to greater using the example of human covenants

1. Even a man-made covenant, once ratified, cannot be annulled or added to (Galatians 3:15)
2. How much more, then, is God's covenant with Abraham unchangeable

B. Paul argues from chronology (Galatians 3:17)

1. The Covenant of Grace is first established with Abraham in Genesis 12–17
2. The law came 430 years after the covenant with Abraham and therefore cannot annul it
3. A parallel chronological argument appears in Romans 4: circumcision came after Abraham was counted righteous by faith and is a seal, not the means, of righteousness

C. Application to the Galatian error

1. The Judaizers erred in adding law-keeping to faith — they missed the details
2. The law has a purpose (a guardian until Christ comes), but it is not to undo or replace the Covenant of Grace
3. The Covenant of Grace spans from Abraham forward as one unchanging covenant; God's manner of saving his people does not change

II. Your Justification Is Secured Through the Terms and Benefits of This Covenant

A. The terms of the Covenant of Grace are God's promises (Galatians 3:16-18)

1. The recurring refrain in Genesis 12–17 is God's "I will" — I will bless, I will give descendants, I will give land
2. The Covenant emphasizes God's plan, God's grace, and God's initiative (John Stott)
3. Abraham believes God's promises and that faith is counted to him as righteousness; he merits nothing by his own goodness
4. God alone walks through the animals in Genesis 15; Abraham does not — God takes the covenant oath upon himself

B. The benefit of the Covenant is an inheritance secured through the one Offspring

1. Paul emphasizes the singular "offspring" in Galatians 3:16: the promise points ultimately to one — Christ
2. Christ is the Offspring of the woman promised in Genesis 3:15 and the Offspring of Abraham
3. Christ redeemed us from the curse of the law by becoming a curse for us; he is the only object of saving faith
4. The blessing comes to the nations through Christ as head — to be united to him by faith is to receive the blessing given to Abraham
5. This leads to Galatians 3:29: those who are Christ's are Abraham's offspring, heirs according to promise

C. The inheritance does not and cannot come by the law (Galatians 3:18)

1. If the inheritance came by the law, the promise would be void — but the promise has not been voided
2. It is still by promise, a promise that culminates in Christ

III. Lessons from the Covenant

A. God is patient

1. The many generations from Abraham to Christ show that God works out his plan slowly and in his own time
2. He is patient toward us, working out his plan to save us

B. God is purposeful

1. He orchestrates all of history to bring about Christ according to his plan
2. His purpose will not fail

C. We do not have to perform

1. Christ has already performed on our behalf for our justification
2. Like a beneficiary of a promise, we can do nothing to fulfill the promise ourselves — we can only trust God to keep it
3. Our justification rests on faith in what Christ has done, not on our own goodness or works
4. The benefits have already been secured; we can add nothing