People think that Jesus was a Jew because the documents in the New Testament (not to mention apocryphal gospels) clearly indicate that he was. If you believe that those documents are historically valid, then Jesus’ Judaism logically follows.

Why do some people think otherwise? One reason is that, then as now, definitions of what it means to be a Jew vary. As the founder of a new world religion, one can argue that Jesus’ Judaism was very different from that of the Pharisees or Sadduccees. So different that they themselves might not have considered him a Jew—in the sense of holding Jewish theological beliefs. But they would still have considered him an ethnic Jew in the sense of having a Jewish mother.

The problem with that, however, is that the genealogies tracing Jesus’ ancestry back to David only refer to that of his adopted father, Joseph. We have no New Testament genealogy for Mary. It’s not impossible that Mary, being Galilean, might have been a Gentile child, possibly adopted into a Jewish family; or that Jesus’ father might have been a Roman soldier, as the Talmud speculates. If so, Jesus would, ethnically, be a Gentile. There is no evidence or reason to think so, other than the curious fact that no gospel spells out Mary’s ancestry.

It’s also possible that Jesus never existed in the first place. To be Jewish, first you have to exist.

I’m not arguing for any of these options, I’m only pointing out that based on the reliability (and lack thereof) of the historical documentation, it is just barely possible that Jesus was not a Jew. There’s no hard evidence proving that he was, and no hard evidence proving that he wasn’t. The existing documentation, in my opinion, suggests that he existed and that he was Jewish. But that documentation is anything but dependable. Belief in his Jewishness, like belief in his divinity, is a matter of faith.

The difference being, belief in his divinity matters, and belief in his ethnicity doesn’t. Would it really matter if Jesus were Irish, or Japanese, or a Kurd? What matters is his message, his actions, his significance: his being Jesus.

There was a recurring sketch on Mad TV of an American evangelical Christian saying stupid things; in one skit, the Christian lady said “Jesus wasn’t Jewish; his name was Christ, not Christowitz!”. I haven’t come across any argument against Christ’s Jewish identity that isn’t similarly moronic and bizarre. To quote from Monty Python’s “The Life of Brian”, Jesus was “A Red Sea Pedestrian, He was Kosher!”. When He quoted scripture, He referred exclusively to the Old Testament; not the Bhagavad Gita, the Gathas of Zoroaster, or Greco-Roman mythology.

Jesus was born of a Jewish mother, and even if he was conceived by the Holy Spirit, rather than Mary’s husband, Joseph, according to traditional Jewish law, he was as Jewish as a boring Saturday, or a meatless lasagna. Jews recognize that he was Jewish, if not the promised Messiah, and according to the Gospels, it was the Jewish clergy who wanted him dead, because they regarded him as a Jewish heretic, who threatened their legitimacy. To say that Jesus wasn’t Jewish is as absurd as claiming that Socrates was, in fact, an Aztec, or that Confucius was Polish.

Jesus of Nazareth was a Jew.

• All those times in the Bible when it describes him going to or speaking in the temple, that was the Jewish temple.
• He attended synagogue (Mark 1:21, Luke 4:16) and observed Jewish feasts such as Passover (Matthew 26:17-19) and Hanukkah (John 10:22). That’s because he was a Jew.
• The Gospel of Luke (Luke 2:21) says he was circumcised, according to a Jewish custom that didn’t become common among Gentiles until much later.
• He and his disciples adhered to Jewish dietary laws including the kosher dietary restrictions outlined in the Torah.
• He observed the Sabbath, attended synagogue and engaged in Sabbath-related activities (Mark 1:21, Luke 6:6-11).

When Jesus said he had not “come to abolish the law”, he was speaking of the law of Moses, the Old Testament law that was the foundation of Judaism. Here’s what he is supposed to have said:

Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. For truly I tell you, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law until everything is accomplished. Therefore anyone who sets aside one of the least of these commands and teaches others accordingly will be called least in the kingdom of heaven, but whoever practices and teaches these commands will be called great in the kingdom of heaven.

In this passage, Jesus is saying that only those who follow the law of Moses—Jews, in other words—will enter the kingdom of heaven. A lot of people seem to have missed that.

Of course, some Christians believe that Jesus’ sacrifice fulfilled the requirements of the Old Testament Law, making it unnecessary for believers to follow the ceremonial and sacrificial aspects of the Law. Others believe that while the new covenant brings a new understanding of salvation through faith in Jesus, it does not abolish the moral and ethical principles of the Old Testament Law.

Neither belief is directly stated or refuted by scripture, not that scripture ever exactly contained God’s Clear And Concise Guide to Living in the Here and Hereafter so many act as if it does. If you look at the right pages in the right way, it can say what you want it to say.

As long as you want it to say Jesus was Jewish. That part’s crystal clear.