In Jewish circles, there is a commonly-held and widely-taught belief that when a Jew believes in Jesus, he is no longer a Jew, but a Christian. Let’s explore this idea, considering where it came from and why it persists, and then discover from the Scriptures why it’s completely wrong.

It Depends On How You Define “Jew”

The entire premise that a Jewish person can stop being a Jew hangs on the definition of “who is a Jew?”

If we define a Jewish person only as someone who is an adherent to Judaism, then Jewish Buddhists and Jewish atheists are also no longer Jews. Yet this claim is only made about Jewish believers in Yeshua.

And what if we define a Jewish person as someone who was raised in a Jewish home with a Jewish identity? Many Jewish believers were also raised in Jewish homes and retain their identity, yet they are rejected. At the same time, there are people of Jewish descent who were adopted, or raised in Jewish homes with little to no Jewish expression. Yet no one claims that these are not Jews.

The reality is that one’s religious beliefs or perceived identity are subject to change. There remains, then, only one immutable characteristic that can reliably be used to determine Jewishness, and that is ethnicity—a person’s physical lineage. If one is a Jew by birth, he will be a Jew until death.

So if ethnicity, which never changes, is what defines Jewishness, then a Jewish believer in Jesus is still a Jew. No matter what he does, what he thinks, or what he believes, it cannot affect or change his ethnicity and physical lineage.

Obviously, then, this was never what the criticism of Jewish believers was intended to mean. The objection to Jews believing in Jesus has instead always been about the unique and contentious relationship between Judaism and Christianity.

Why Do Jews Object to Believing in Jesus?

So why do so many Jews object to the idea that a Jew can believe in Jesus and still be a Jew? There are several reasons.

The first is historical. Although nearly all of the first tens of thousands of believers in Jesus were Torah-keeping Jews, this fact is lost to much of the Jewish world. The history that they do remember, however, is that Jews have been horribly persecuted in the name of Christianity, partly due to the anti-Semitic propaganda that “the Jews killed Jesus.”

Belief in Jesus is also a threat to the authority of Judaism. If the teachings of Yeshua and the New Testament are given greater weight than that of the Talmud and the Rabbis, this undermines Judaism as a religious system, just as Yeshua Himself was perceived as a threat to the religious authorities of His day.

There are also theological objections to fundamental ideas of Messianic faith, such as Yeshua being the Son of God. While such concepts might initially seem foreign and even contrary to Jewish thought, an honest reading of the Hebrew Scriptures reveals that their origins are, in fact, quite Jewish.

Finally, perhaps the most overt obstacle to Jews believing in Jesus is cultural. The vast majority of Jewish believers throughout history eschewed Judaism and adopted not only the beliefs, but also the cultural trappings of Gentile Christianity. The most obvious examples of this are Sabbath and holiday observances, as well as diet—all of which change dramatically when a Jew “converts” to Christianity.

In the twentieth century, this objection was partially overcome by the advent of Messianic Judaism, which sought to distance itself from traditional Christianity through the reclamation of Jewish traditions and Torah observance, as well as a rejection of anti-Semitic theology. While there is much variation in practices and beliefs among Messianic Jews—and while Messianic Judaism has its own issues concerning Rabbinic authority versus the authority of the Scriptures—Messianic Judaism nevertheless challenges the presumption that belief in Jesus necessitates conversion to a Christian religion, and demonstrates that Jewish culture and belief in Jesus can be compatible.

Do the Scriptures Say Who Is a Jew?

All objections aside, it is obvious from the entire biblical record that a Jew is anyone who descends from the patriarch Jacob, specifically through the tribe of Judah (sometimes including the remnants of other tribes, cf. Acts 21:39, Romans 11:1). Beyond physical descent, then, no other stipulation for claiming Jewishness is found in the Scriptures.

Nevertheless, there remains one more Scriptural definition for “who is a Jew?” that most Jewish people would never consider:

For one is not Y’hudiy [a Jew] who is only so outwardly; neither is circumcision that which is only outward in the flesh. But one is Y’hudiy who is also so inwardly, and whose circumcision is also of the heart—in the ruach (Romans 2:28-29a, MJLT; cf. Deuteronomy 30:6).

In other words, while physical lineage is necessary, it is actually belief in Yeshua—which results in circumcision of the heart—that defines a Jew’s truest Jewishness. Not only is believing in Yeshua not a disqualifier for being a Jew, it is actually a requirement!

Jewish believers in Yeshua, especially those who have not adopted cultural Christianity, can stand confidently against the accusation that they are no longer Jews. The testimony of Scripture makes it clear: Jews who believe in Jesus are the most Jewish Jews of all!