>>23895 (OP)
I don't know much about gnosticism, but the NT itself does a perfectly-good job of explaining the purpose of the OT law and that justification by faith alone was always God's plan, even before the law was ever given:
>"16Now 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. 17And 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. 18For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise. 19Wherefore 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. 20Now a mediator is not a mediator of one, but God is one. 21Is 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. 22But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe. 23But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed. 24Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. 25But after that faith is come, we are no longer under a schoolmaster." Galatians 3:16-25 KJV
>"1What shall we say then that Abraham our father, as pertaining to the flesh, hath found? 2For if Abraham were justified by works, he hath whereof to glory; but not before God. 3For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. 4Now to him that worketh is the reward not reckoned of grace, but of debt. 5But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness. 6Even as David also describeth the blessedness of the man, unto whom God imputeth righteousness without works, 7Saying, Blessed are they whose iniquities are forgiven, and whose sins are covered. 8Blessed is the man to whom the Lord will not impute sin. 9Cometh this blessedness then upon the circumcision only, or upon the uncircumcision also? for we say that faith was reckoned to Abraham for righteousness. 10How was it then reckoned? when he was in circumcision, or in uncircumcision? Not in circumcision, but in uncircumcision. 11And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed unto them also: 12And the father of circumcision to them who are not of the circumcision only, but who also walk in the steps of that faith of our father Abraham, which he had being yet uncircumcised." Romans 4:1-12 KJV