Isn’t that like being a Corporal-Captain?
No.
Remember when the Apostle Paul, under the inspiration of the Holy Spirit wrote,
For we are the circumcision, who worship by the Spirit of God and glory in Christ Jesus and put no confidence in the flesh— though I myself have reason for confidence in the flesh also. If anyone else thinks he has reason for confidence in the flesh, I have more: circumcised on the eighth day, of the people of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; as to the law, a Pharisee; as to zeal, a persecutor of the church; as to righteousness under the law, blameless. But whatever gain I had, I counted as loss for the sake of Christ. Indeed, I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord. (Phil 3:3-8a emphasis added for skimmers)
Here is something from a great website (that all of the Catholics on FR should bookmark and ask their questions):
Paul was a Jew who took great pride in his Jewish heritage. He lays out his Jewish credentials in Philippians 3:5–6: “If someone else thinks they have reasons to put confidence in the flesh, I have more: circumcised on the eighth day, of the people of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; in regard to the law, a Pharisee.”
The fact that he was circumcised on the eighth day means that his parents followed the commandment God gave to Abraham in Genesis 17:2. He was an Israelite from the tribe of Benjamin, one of the two tribes that remained loyal to David’s line after the kingdom divided (see 1 Kings 12). It is also interesting that Israel’s first king, Saul, was of the tribe of Benjamin and Paul’s Hebrew name was Saul.
Although Paul was a Roman citizen (Acts 22:28) of the city of Tarsus (Acts 21:39), he was “a Hebrew of Hebrews,” meaning that he was raised according to Hebrew law and culture. He eventually moved to Israel and became a Pharisee (cf. Acts 26:5), which means that he was dedicated to keeping the Law in minute detail.
SOURCE: GotQuestions.org
Finally, to whom was the Book of Hebrews written? Catholics? No! it was to Jewish believers in Jesus Christ.
A Messianic Jew - sometimes called a "completed Jew" IS a Christian (because they have received our Lord and Savior and have trusted Him, by faith to restore the broken relationship with God that was evident since the day of their conception) and IS a Jew.
Your question exposes your misunderstanding - but that's okay, until now.