Why can’t the Hebrews believe all of what the New Testament has to say about God (blessed be He), about Jesus (peace be upon him), and about Salvation?

Why can’t the Hebrews believe all of what the New Testament has to say about God (blessed be He), about Jesus (peace be upon him), and about Salvation?

Hebrews can’t believe the N. T. because, in order for the N. T. to be the inspired word of God, it must perfectly agree with was already proven to be the “Real” Word of God (the Hebrew Scriptures). Thus, if we are able to prove that the N. T. openly contradicts the Hebrew Scriptures, we would have thereby proven that the N. T. isn’t the inspired word of God.
Does the N. T. openly contradicts the Hebrew Scriptures? Of course! And the proof? The apostle Paul (p. b. u. h. ), who teaches that he who gets circumcised cannot be “saved”, as he has fallen from “the grace”. As it has been said: «Behold, I Paul say unto you, that if ye be circumcised, Christ shall profit you nothing. For I testify again to every man that is circumcised, that he is a debtor to do the whole Law.
Christ is become of no effect unto you, whosoever of you are justified by the Law; ye are fallen from grace» (Galatians 5: 2-4). And why does the former contradict the Hebrew Scripture? Because the latter goes on to say that, it is the incircuncised who will be prevented from entering Paradise (the heavenly Jerusalem). As is said:
"... Put on your beautiful garments, Jerusalem, the holy city! For the uncircumcised and the unclean will no longer enter you" - Isaiah 52: 1, Christian Standard Bible. Likewise, the gospel contradicts Hebrew Scripture, when it claims that it is impossible for a prophet to die outside Jerusalem (" because it is not possible for a prophet to perish outside of Jerusalem" - Luke 13: 33); whereas Hebrew scripture teaches that not only Abraham, ISaac and Jacob (all of whom were prophets), but even Moses (the greatest of all prophets) died outside of Jerusalem.
As is written: " So Moses the servant of the Lord died there in the land of Moab, according to the Lord’s word" - Deut. 34: 5, C. S. B.

The New testament is good; but beware, as it is plagued with contradictions

The New testament can be a powerful tool to make Gentile peoples come to embrace Bible’s monotheism. But the New testament isn’t perfect, as it’s pages are plagued with brazen contradictions.
Let’s consider one example: Suppose someone comes to you making the following claim-- “I believe salvation comes from faith in Jesus perfect obedience to God’s Law, and not from my imperfect obedience to anything the Law has commanded; But, since I was born in a Jewish home, and I also happen to be circumcised, I must therefore observe the Jewish feasts prescribed by the Law”. Would you believe anything else said by such person? Wouldn’t you consider him to be a brazen liar?
If so, then why was it o. k. for Paul to preach “salvation by faith [and without the works of the Law]” while at the same time he would personally keep observing the feast prescribed by the Law? As is written: «When they desired him [Paul] to tarry longer time with them, he consented not; But bade them farewell, saying, “ I must by all means keep this feast that cometh in Jerusalem”: but I will return again unto you, if God will”»- Acts 18: 20-21, KJV.

«No man should act as a judge in a cause he loves, or a cause he hates, for he isn't likely to find fault in what he loves, nor find merit in what he hates»

How are sins forgiven?

If God’s Law (the Torah, the Prophets, and the Writings) states that forgiveness of sins comes through sincere repentance (“Perhaps the house of Judah will hear all the calamity that I am planning to do to them, in order that they may turn, each one from his evil way. Then I would forgive their iniquity and their sin…The sacrifices of God are a broken spirit. A broken and a contrite heart, O God, You will not despise. ”- Jeremiah 36: 3, & Psalm 51: 19, Tree Of Life Bible); And then comes the Gospel and tries to refute the Law, claiming instead that forgiveness of sins doesn’t come through sincere repentance, but rather through belief in Jesus (“that all who believe in him will receive forgiveness of sins through his name” - Acts 10: 43); Then the disputation between Christians and Hebrew believers is finally settled; the case has been closed, and there’s nothing else to discuss. Why? Because the truths revealed in the Law [the Hebrew Scripture] are final and irrevocable [since the Law cannot be abrogated or broken, according to Deuteronomy 4: 2]. And the gospel seems to agree with this, when it quotes Jesus saying the following: “… and the Scripture [the Law] cannot be broken” (John 10: 35)