This is a fascinating question. And it goes to the heart of religion. Religious people tend to put what a casual observer might call “an oversized meaning to a minor detail.” For instance, among Christians, there might be some debate over just how important is the Virgin Birth within the context of the whole of Christianity. For some people, it might be considered a nice but unnecessary detail, for others it might be a part of the indivisible and undisputed core of Christianity without which one cannot be called Christian.
This same phenomenon holds for every religion. This is why Sunni and Shiite Moslems have been at each other’s throats for centuries.
So, back in the day, not long after Jesus’ Death, Resurrection, and Ascension, the infant Church has a number of decisions to make. One was, should this newly named thing called Christianity be just another sect of Judaism like the Essenes, or the Pharisees, or the Scribes, or the Sadducees, or any of a pretty big handful of Jewish sects then known. The alternative was that they separate themselves from Judaism completely and become something else. There were multiple elements to this decision. Would we require that male Christians be circumcised? What, if any role would the Hebrew scriptures play? Would the dietary laws of the Jews be observed among Christians? Would the Jewish holidays be observed among Christians; for instance, the Passover which would conflict with Easter, and what about Yom Kippur, the day of Atonement which would theologically conflict with the victory of Jesus over sin?
A meeting was held among the Apostles to make the decisions about such things. During the confab they heard from a number of Apostles who had been out there and had converted a number of both Jews and Gentiles. If you want to learn more about this, read Acts chapter 15. The conclusion is contained in a letter written from this conference to the various churches; the letter follows here:
Acts 15:23-29
Greetings.
We have heard that some went out from us without our authorization and disturbed you, troubling your minds by what they said. So we all agreed to choose some men and send them to you with our dear friends Barnabas and Paul— men who have risked their lives for the name of our Lord Jesus Christ. Therefore we are sending Judas and Silas to confirm by word of mouth what we are writing. It seemed good to the Holy Spirit and to us not to burden you with anything beyond the following requirements: You are to abstain from food sacrificed to idols, from blood, from the meat of strangled animals and from sexual immorality. You will do well to avoid these things.
Farewell.
That is a very minimalist version of the Jewish religion. Very. So in that conference the Apostles decided that Christianity would not be Jewish, but that it would be something else. As a result, Messianic Jews observe both Judaism and Christianity in all of their complexity. With that exception, Jews who convert stand to lose a whole lot. It often costs them friends and family as well as business contacts. They are often shunned and treated as though they no longer exist. The Old Testament is full of the consequences of chasing after other gods, and that is how Jews who convert are viewed within that community that they have lived in since birth.
So, think about this, each of you. Just exactly what was the price that you had to pay in order to become a Christian yourself? What did you lose? How were you punished for your choice? How expensive was your faith? The Article about Blandina and her companions just before this in the newsletter might give you some context.