Matthew 26:28 For this is my blood, which ratifies the New Covenant, my blood shed on behalf of many, so that they may have their sins forgiven.
Hebrews 13:20 The God of shalom brought up from the dead the great Shepherd of the sheep, our Lord Yeshua, by the blood of an eternal covenant.
Hebrews 9:15 It is because of this death that he is mediator of a new covenant [or will].g
Because a death has occurred which sets people free from the transgressions committed under the first covenant, those who have been called may receive the promised eternal inheritance.
Romans 4:13 For the promise to Avraham and his seed that he would inherit the world did not come through legalism but through the righteousness that trust produces.
The promise did not come through legalism, AND it does not lead to it. Having begun in the Spirit we do not fall back into physical legalistic observances. Torah is Spirit and is to be 'observed' in the Spirit. First covenant, and second. Both could never make people righteous by mere observance, but by FAITH in what was said. By Faith Avraham was declared righteous, and out of faith did he observe what was told him. His observance means nothing without faith. And his observance (circumcision) was not the goal of his faith. The goal of his faith is eternal life, life from the dead. That all nations will be blessed through his 'seed' (Yeshua) not seeds (Yisrael and the nations). We are blessed and found righteous because of the faith we have, like Avraham. Gentiles are instructed to circumcise their hearts with the Spirit, not their flesh with the stone. They are told by God that they inherit along side us Jews, not because they became one of Avraham's 'seeds', but because they became one of Avraham's children through the 'seed', through faith. Not through becoming adopted among the seeds.
If the whole saved world becomes adopted into the commonwealth of Yisrael, who will be the nations that come up to him in the olam haba? The whole world was saved to become Jewish and observe Jewish law?
Very foolish indeed to lead gentiles into Jewish customs and tradtions with the notion they ARE JEWS under an 'eternal Mosaic' law. This is found in scripture, in the very book Charles is refering to. (Galatians).