The Law of God was written down that's true, but it already existed, which is how men knew they sinned.
Galatians 3:24,25 KJB, etc:
Verse 24 and 25 also refer to the Moral Law also, in that it too leads us, by its demand for perfect obedience to Christ, for without Him, we cannot comply with its perfect way of living, for Christ Jesus is the Living embodiment of it, since it is merely a written transcription of His Living character. Thus the Law of Ten Commandments upon stone while the Moral Law of God, Jesus Christ Himself is the eternal Living example, everlasting Living Demonstration of it in action, lived out perfectly. Yet the Ten Commandments upon stone is not enough, for it must by the means of Christ Jesus, be written upon our hearts, that we too, as Christ Jesus, may live it out in the life, even eternally as He does.
What then of Vs 25? No longer “under a schoolmaster”, if the “Law” of Galatians 3:24 refers not only to the ceremonial laws, but also to the Moral Law itself as given in the Ten Commandments upon stone tables? Well, this question was given in another way by Paul, in Romans 3:19-31 and in Hebrews 8:8-13, 10:16, etc.
Notice, that being “under the law” or even “schoolmaster” [speaking at this time of the Moral for the moment], meant to be living in condemnation, for by it [the Moral Law] is the knowledge of sin [Romans 3:20; 1 John 3:4, etc], and we would be under its penalty [second death, Romans 6:23] for any and all transgression of it. Thus, by that knowledge, of condemnation because of our transgressions, we would also recognize [or see] the need of a [the] Saviour, Jesus Christ, who would save us “from” [Matthew 1:21] our sins.
The ceremonial laws and the Moral Law cannot save, but Jesus Christ can. Therefore, the ceremonial laws were given to point to Christ Jesus as how He would saves us from our sins [transgression of the Moral Law] and the Moral Law as written upon stone tables, revealed the very severity of our lost condition, and so look unto God for salvation from transgression/sin.
Thus, so we need the ceremonial laws? Only as in their reality, anti-type, Christ Jesus and that which He does in the Heavenly sanctuary. Therefore we need Him as the sacrifice, His blood, His High Priestly ministry in the Heavenly, etc. We are to be living sacrifices, giving the sacrifices of praise, living to the glory of God for so great salvation, etc.
Thus, so do we need the Moral Law? Yes, but not merely externally [as only that which condemns all sin], once we have seen our need of Jesus Christ as Saviour from the 2nd death, but more importantly that it should be written internally [that is upon the heart/mind, Jeremiah 31;31-34, etc] by the Holy Spirit, to be lived by the power/strength given of God by Jesus Christ through the Holy Spirit indwelling.
We see it not as the schoolmaster to lead us to Christ, after that we have Christ Jesus, but we see it presently as the perfect promises of God [God says, I promise, in Christ Jesus, fulfilling my Everlasting Covenant, that Thou shalt not steal... not commit adultery, not kill, and that thou shalt honour thy father and mother, and thou shall Remember to keep the Sabbath day holy, etc, etc, not as mere prohibitions, but as His faithful promises to us, in what He would work out in us, by/through faith in Him, in what He accomplishes/finishes] as the way to live in Christ Jesus, for He demonstrates it in love for us by the way in which He continually lives.
I no longer have to think upon the Moral Law, as to how shall it be done, accomplished in my own strength, but rather I, in salvation offered of God, look now to Christ Jesus and His strengthening of me, and say, Ah! I see [in the life of Jesus], that is how it [the will of God, His Law, Character] is done, that is how it is obeyed, to be lived, to be followed, to be practiced, to be taught [not something of mere words, but of demonstration], etc. It is the difference between a textbook explanation of something, and experiencing the real live demonstration and practice of that which was explained in the textbook.
Therefore, does Galatians get rid of the Moral Law? No. What it does do, is it takes the Moral Law from merely a written theory [also a condemnation] to the very real practical demonstration [and fulfillment of their promises, thus no longer condemnation] in the Christian Life. Merely saying, “Lord, Lord” and not “doing” the things which Jesus said to do, is not enough. It is as the righteousness of the Pharisees, as of Nicodemus. Ours must far exceed that. Our righteousness must be of Christ Jesus. Wherein He said, “... I have kept my Fathers Commandments and abide in His love.”
1 Thessalonians 4;9 KJB - But as touching brotherly love ye need not that I write unto you: for ye yourselves are taught of God to love one another.
Therefore, is the promises of God [of the New Covenant, and to inherit the New Heaven and New Earth] against the Law of God?
Galatians 3:21 KJB - 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.
Therefore, since the Law of God is not “against” the promises, they work in harmony and atonement with them, serving its purpose.
Thus as I stated: