I think Moses was speaking from the spirit "behind" the law, which is, "the just shall live by faith". To approach the law in humility and a sense of neediness for the help of god has always been righteous.
The stumbling block became that they pursued it in their own righteousness rather than thru the sensibility of justice, mercy, and faith.
Thus, the letter kills and the spirit gives life.
IMO, None of that has changed. The veil that covers the minds of those who read the law without the spirit of faith, also covers the minds of those who read the NT in the letter.
Say not who will ascend into heaven(to bring Christ down by acting as if anyone else could do it in their own righteousness)
Say not who will descend into the pit(as if anyone could come back from death on their own)
Speak from the spirit of faith, the faith of Abraham, who trusted God and it was "accounted to him as righteousness".
If faith was accounted to Abraham for righteousness and he was, "the friend of God", Why did God put his children under the law? Why not continue in the faith of Abraham?
19 Why the Law then? It was added because of transgressions, having been ordained through angels by the agency of a mediator, until the seed would come to whom the promise had been made.(promise that from Abraham's seed would come children as the sand on the shore, the stars in the sky... THE SALVATION OF ALL :o)
Paul says the law given 400 years later cannot annul or transcend the previous covenant of faith established through Abraham.
But when the fullness of the time came, God sent forth His Son, born of a woman, born under the Law, 5 so that He might redeem those who were under the Law, that we might receive the adoption as sons. 6 Because you are sons, God has sent forth the Spirit of His Son into our hearts, crying, "Abba! Father!" 7 Therefore you are no longer a slave, but a son; and if a son, then an heir through God.
But now that faith has come, we are no longer under a ]tutor. 26 For you are all sons of God through faith in Christ Jesus. 27 For all of you who were baptized into Christ have clothed yourselves with Christ. 28 There is neither Jew nor Greek, there is neither slave nor free man, there is neither male nor female; for you are all one in Christ Jesus. 29 And if you belong to Christ, then you are Abraham's descendants, heirs according to promise.
Heirs do not work for an inheritance. It is theirs by birthright. They are free.
For the promise is to you and your children and to all who are afar off, even as many as the Lord our God shall call to Himself(Acts 2 first sermon on Pentecost- initial invitation:o).
"in order that in Jesus Christ the blessing of Abraham might come to the Gentiles so that we might receive the promise of the Spirit through faith"
Also, something to ponder, until Moses gave the law, there was no law except the spirit of Abraham's faith and the law of righteousness displayed in creation so, the Israelites were not religious yet- at the point in which Moses gave them Deuteronomy 30:11-14
The spirit of faith in which we speak is the faith of Abraham our father and Jesus Christ the image of God, "the life I live I live by the faith of the son of God", a humble faith, meek and lowly of heart, full of mercy and good fruit.