It's just that our source for life is not by trying to live the law but our walk is by faith...
Certainly all who depend on the actions of the Law are under a curse. For it is written, "A curse on everyone who does not obey everything that is written in the Book of the Law!" Now it is obvious that no one is justified in the sight of God by the Law, because "The righteous will live by faith." But the Law has nothing to do with faith. Instead, "The person who keeps the commandments will have life in them." The Messiah redeemed us from the curse of the Law by becoming a curse for us. For it is written, "A curse on everyone who is hung on a tree!" This happened in order that the blessing promised to Abraham would come to the gentiles through the Messiah Jesus, so that we might receive the promised Spirit through faith.
(Gal 3:10-14) (ISV)
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For as many as are of the works of the law are under a curse: for it is written, Cursed is every one who continueth not in all things that are written in the book of the law, to do them. Now that no man is justified by the law before God, is evident: for, The righteous shall live by faith; and the law is not of faith; but, He that doeth them shall live in them. Christ redeemed us from the curse of the law, having become a curse for us; for it is written, Cursed is every one that hangeth on a tree: that upon the Gentiles might come the blessing of Abraham in Christ Jesus; that we might receive the promise of the Spirit through faith.
(Gal 3:10-14)
Again, Paul is not saying anything new, but is quoting from the Torah and Tanach.
Neh 9:29 And testifiedst against them,
that thou mightest bring them again unto thy law: yet they dealt proudly, and
hearkened not unto thy commandments, but sinned against thy judgments,
(which if a man do, he shall live in them
and withdrew the shoulder, and hardened their neck, and would not hear.
Hab 2:4 Behold, his soul which is lifted up is not upright in him:
but the just shall live by his faith.
Rom 1:17 For therein is the righteousness of God revealed from faith to faith: as it is written,
The just shall live by faith.
Rom 1:18 For the wrath of God is revealed from heaven
against all ungodliness and unrighteousness of men, who
hold the truth in unrighteousness;
Rom 1:19 Because
that which may be known of God is manifest in them; for God hath shewed it unto them.
If one understands the OT scriptures, then one will understand what Paul is saying. Paul is not changing the OT, no, that would be mocking Yah who never changes. Paul is not changing the message, he is fully preaching (pleroo) the OT, same as Jesus/Y'shua fully preached (fulfill/pleroo) the Torah and prophets.