I'll say it again, just in case some are hard of hearing...
The NEW Covenant was PRIOR to the giving of the law and the old covenant. How do those in Christ know this?
It's simple, by study of what Apostle Paul taught, and by looking at the Old Testament Book examples of the appearance of Lord Jesus to Abraham in his day. Come with me in Galatians 3 by Apostle Paul, and learn by line upon line coverage, which is the only way to really learn God's written Word...
Gal 3:1-5
3 O foolish Galatians, who hath bewitched you, that ye should not obey the truth, before whose eyes Jesus Christ hath been evidently set forth, crucified among you?
2 This only would I learn of you, Received ye the Spirit by the works of the law, or by the hearing of faith?
3 Are ye so foolish? having begun in the Spirit, are ye now made perfect by the flesh?
4 Have ye suffered so many things in vain? if it be yet in vain.
5 He therefore that ministereth to you the Spirit, and worketh miracles among you, doeth He it by the works of the law, or by the hearing of faith?
KJV
Some among the Galatians had apparently been twisting the Truth of The Gospel regarding the difference between following The Spirit by Faith, vs. law keeping. Back in Galatians 1, Paul gave rebuke about the Judaizer Pharisee converts that had crept in, and were distorting The Gospel into "another gospel" which Paul and the Apostles did not preach. Thus Paul is continuing his lesson on that here to the Galatians (and to us, as Galatians is a foundational Book of Christian Doctrine.)
Gal 3:6-9
6 Even as Abraham believed God, and it was accounted to him for righteousness.
7 Know ye therefore that they which are of faith, the same are the children of Abraham.
8 And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, "In thee shall all nations be blessed."
9 So then they which be of faith are blessed with faithful Abraham.
KJV
Does the above just mean, that because Abraham believed God's Promise through Faith, that meant all nations would be blessed materially, or physically? God forbid, NO!
The Gospel of Jesus Christ was literally... preached first to Abraham. That... is what Paul is pointing to. Even towards the end of John 8, Lord Jesus said that Abraham rejoiced to see His day, and was glad. What day of Christ's was Lord Jesus pointing to, do you think? To the time of His death and resurrection of course, which is THE GOSPEL.
Abraham KNEW about The Gospel, but just didn't get to live to the time when Jesus would come to die on the cross and be resurrected by The Father. The Gospel of Jesus Christ coming to die on the cross is actually first hinted at in Gen.3:15 about Christ's heel being bruised upon His cross. King David would be given to prophesy about events of Christ's crucifixion about 1,000 years before it happened, even about the soldiers casting lots upon Jesus' clothing, per Psalms 22. The prophet Isaiah was given to write of Christ's crucifixion per Isaiah 53. The Gospel of Jesus Christ can be found pointed to in many Old Testament Books of God's Word. That's why it's important to study all of God's Word, and not just the New Testament Books.
Thus Apostle Paul is teaching us, THE GOSPEL BY FAITH was always FIRST, even 430 years prior to the giving of the law and old covenant!
Gal 3:10-14
10 For as many as are of the works of the law are under the curse: for it is written, 'Cursed is every one that continueth not in all things which are written in the book of the law to do them.'
11 But that no man is justified by the law in the sight of God, it is evident: for, 'The just shall live by faith.'
12 And the law is not of faith: but, The man that doeth them shall live in them.
13 Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, 'Cursed is every one that hangeth on a tree:'
14 That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.
KJV
The 'blessing' of who? The "blessing of Abraham", which is what? It is the receiving of "the promise of the Spirit through faith"! Wait a minute. That blessing of Abraham from GOD was way... before God gave Israel the law and old covenant through Moses? Do you know what that means brethren?...
... It means, The NEW Covenant Jesus Christ, The Gospel, was always FIRST... before the law, and before the old covenant!
Why don't the Churches teach about the NEW Covenant always being first??
It's almost like many Christian Churches today have succumbed to ideas of the Judaizers who want us to understand The Bible like the evolutionists do with earth history, like earth history began with the cave man and slowly progressed to now. Just because the orthodox Jews can't understand this, doesn't mean those of us in Christ Jesus have to put up with their... version of Bible history. What Paul taught here in Galatians 3 has been written all along, and it is even pointed to in the Old Testament Books. Paul also covered this very subject in Romans 4 also.
Apostle Paul here in Galatians 3 is showing us that God's Plan of Salvation through His Son Jesus Christ, The Gospel, The New Covenant, was always His 'original' Plan from the beginning.
Gal 3:15-18
15 Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.
16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
17 And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
18 For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.
KJV
Sounds a bit like Paul is kind of talking in circles, but really he is not. He saying that God gave Abraham the "covenant" by promise not by the law, for the law was 430 years later. Thus the law which came later, cannot disannul the promise to make it of no effect.
Thus God's Promise by Faith, and His blessings of inheritance to Abraham, is BY PROMISE, and not by the law. This is important, because the Judaizer instead thinks this inheritance is by the law.
Gal 3:19-21
19 Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator.
20 Now a mediator is not a mediator of one, but God is one.
21 Is the law then against the promises of God? God forbid: for if there had been a law given which could have given life, verily righteousness should have been by the law.
KJV
Why then did God 430 years later give the law? It was given "because of transgressions", until the seed would come to whom the Promise would be applied (i.e., Jesus Christ and those of FAITH!).
Gal 3:22
22 But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.
KJV
That... is pointing to God's original Salvation Plan ordained before the foundation of this world! (Ephesians 1:4) That is why we all... have been concluded under sin by the Scriptures, so that the Promise by Faith on Jesus Christ would be given to them that believe. With that Truth then, it means we can go even back further than Abraham with this idea of God's Promise of Salvation through His Son by FAITH! It's about the Promise by Faith on The Gospel Jesus Christ being ordained even before the foundation of this world!
Gal 3:23-29
23 But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed.
24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.
25 But after that faith is come, we are no longer under a schoolmaster.
26 For ye are all the children of God by faith in Christ Jesus.
27 For as many of you as have been baptized into Christ have put on Christ.
28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
KJV
That means, even as a Gentile believer on Jesus Christ, you are counted... as Abraham's seed, and will INHERIT WITH faithful Abraham per God's promises.