Read Galatians 3.
When God called Abraham in Genesis 3 and made what we call the “Abrahamic Covenant” with him, God promised Abraham, “…all peoples on earth will be blessed through you” (Genesis 12:3).
How exactly God intended to fulfill this worldwide covenant promise is not spelled out in Genesis 12. In fact, the Old Testament doesn’t explain it in great detail, though it does give some light on the subject.
Paul quoted Genesis 12:3 here in Galatians 3:8. According to Paul, Genesis 12:3 “announced the gospel in advance” as we read to Galatians 3:8.
But how did God include us Gentiles? Did he do so by making us obedient to the law of Moses? No! Again, according to Galatians 3:8, the promise God made to Abraham was “that God would justify the Gentiles by faith” because Abraham was a man of faith (vv. 6, 9) not a man of the law.
The question Galatians 3 answers is, how can Gentiles be legitimate descendants of Abraham and, thus, partake in God’s promises to Abraham?
Jewish people, of course, physically descended from Abraham, so they are legitimate heirs to the covenant promises of Genesis 12. But how do we Gentiles become heirs?
The answer is through Messiah–Jesus. He descended from Abraham physically. Paul makes a big point about this in verses 16. Genesis 12 promised these blessings to Abraham’s seed (singular) not “seeds.” Paul says that means one person was intended–Jesus. He wrote (again in verse 16), “Scripture does not say ‘and to seeds,’ meaning many people, but ‘and to your seed,’ meaning one person, who is Christ.” It is our connection to Christ–by faith–that makes us eligible for the blessings of the Abrahamic covenant (vv. 26-29), not our obedience to the law (vv. 10-14).
This has implications for what the law means to us as Christians. We no longer need to obey the law–or should obey the law–because Christ unlocked us from the law’s obligations and penalties (vv. 23-25). God’s law reveals to us so much about the character of God and our accountability to him, but it cannot save us or make us holy (vv. 21-22).
Stay away, then, from anyone or any group that says you need Christ PLUS obedience to the law of God or obedience to any other kind of religious ceremony or activity to be saved or sanctified. In Christ we have everything we need–salvation (vv. 8, 11-12) and the Holy Spirit of God (vv. 2-5).