No one could commit the sin Adam and Eve did because an angel with a flaming sword kept all out of the garden where the tree was.
And that is what Rom 5:14 says.
A&E's sin was disobedience. Any particular action does not determine sin; the particular law broken does not determine sin. Disobeying any Word (command) of God is sin and all men have failed to obey God's Word 100%. (Christ excluded, of course.)
Part of the death curse against A&E was their removal from access to the Tree of Life, which alone would have provided them life. (Genesis 3:24) The Angel of the Lord prevented A&E and all mankind from finding life apart from the last Adam (of whom the first Adam was a like representative type).
We already know that all are sinners because all sinned.
Agreed.
But we don't have GOD giving any Gentile nation a law with instructions of blessings and cursings for consequences of keeping that law.
A Gentile is a non-Jew. Apart from the nation of Israel, all races are Gentile races. They have always so been . . from Adam to Jacob, all men were Gentiles. There was no such thing as a Hebrew until Jacob was so designated as the Tribal father, "Israel."
But Israel was given specific instructions of the law given at Sinai that no other nation received.
True, they were blessed with holy ordinances that revealed God's promises of a Redeemer, that no other nation enjoyed. They were an "elect" people.
However, all of Adam's offspring everywhere, remained under the original covenant made between God and Adam in the garden, and the promise of a "Seed" that would be produced from Eve. Genesis 3:15
The Mosaic Covenant and Law established at Mt. Sinai simply reproduced in full detail that original Covenant of Law and the ordinances reiterated he Messianic promise (gospel).
So are you saying that the law made in Genesis 2 is the law that GOD placed on the cross?
I am saying that Jesus Christ was lifted up on the cross, to legally satisfy the eternal Moral Law of God, in the stead of those given to Him by the Father to redeem. That is the Justification of the saints.
The law at Sinai?
Or all decrees ever that the LORD made?
Ultimately, there is only one Law of God. It is specifically laid out in the Decalogue, which remains to this day. The civil and ceremonial laws ended with the death of Christ, but the one Moral Law of God is applicable . . as a living guide to holy living . . even to those who have been justified by the death of Christ.
This is theologically call the "Third Use of the Law."
The first use of God's one Law, was to convict all men of disobedience and sin.
The second use of God's Law (Sinai) was to convict many men of their need of a Savior.
The third use of God's Law is to produce sanctified, holy living on this earth, through the indwelling of the Holy Spirit. Our faith in Christ's obedience, actually establishes the Law. See Romans 3:31
God's one true Law is eternal . . never temporal . . for it is our King's Holy Standard, Commands, will, and Word. See Matthew 24:35
What a King decrees (i.e. Law and Order), and establishes, and seals, cannot ever be revoked.
Spiritual principle: Esther 8:8, Daniel 6:8