At the time of Jesus’ crucifixion, the Jews were a small tribe, mostly confined to Judea. They weren’t considered globally significant. Then the pivotal events in Western civilization occurred: Christ’s crucifixion and resurrection. At Pentecost, God commanded the Apostles (who, of course, were Jews) to go out and spread Christianity. That got the ball rolling. The Apostles were preaching a new religion, rather than traditional Judaism.
Then, in A.D. 70, during the first Roman-Jewish War, the Romans destroyed the Second Temple in Jerusalem. The destruction of the temple, and the subsequent disunity and scattering of the Jews, led to what we now call “rabbinical Judaism.” That is to say, there was no longer a hierarchy and a unified theology. Instead, various Jewish factions, living in various parts of the world, followed the teachings of different rabbis, and had different interpretations of Scripture.
This diaspora led to various groups of Jews having different beliefs and traditions, and that’s probably where we get the old saying, “Two Jews, three opinions.” The Jews spread out, all over the Middle East and into Africa and Europe. Wherever they went, they were regarded as incomers, foreigners—which of course they were—with strange customs that weren’t always compatible with the ways of the people who were already in place.
At the same time, for the next few centuries, Christianity was spreading throughout Europe, and unlike Judaism, it was a proselytizing religion. The first Christian evangelists had a high conversion rate, and by the fourth century A.D. the Roman Empire was largely Christian. The Christians generally disdained the Jews because the Jews didn’t accept Jesus as the divine; moreover, the Christians held the Jews responsible for having killed Christ.
Jews don’t accept Jesus as the Messiah. That’s a less noticeable factor in Jew-hatred today, because gentiles are more secular now, but it’s still an important reason why Jews are hated. The Jewish concept of the Messiah is much more political than the Christian concept. Jews believe that when the Messiah comes, he will come to benefit Jews, above all. Christians believe that the Messiah has already come, in the person of Jesus Christ, and that He came for all mankind.
Making matters worse for the Jews was their inability to acquire real estate. In those days, land and houses weren’t usually sold on the open market. They were almost always kept in the family, passed down from father to son. Thus, it was almost impossible for a Jew to buy land. If a Jew owned real property, at all, it would almost always be commercial buildings, such as multifamily dwellings. So, the “Jewish landlord” became another stereotype.
Most Jews, to make a living, had to go into business—usually as a middleman. Handling money—“changing” it—was considered a dirty occupation, not fit for Christians. That’s why Jews were the moneylenders, wholesalers, brokers, and so on—and often are, today. Who doesn’t hate middlemen, financiers, and landlords?
Jews who were less fortunate usually had to live in slum areas of large cities, in squalid conditions: hence the stereotype of the “Dirty Jew.” Jews were regarded as a sort of vermin, in many parts of the world, and the governments of these various nation-states were always trying to force them out: either confining them to ghettos, or banishing them altogether. Jews were constantly on the move, and were generally regarded as vagabonds.
“Maybe that’s why we always wear our hats.” - Tevye, Fiddler on the Roof
Even in places where they were tolerated, Jews were regarded as interlopers, and as cosmopolitans: almost as undesirable as Gypsies. They kept to themselves; they looked different, physically; they tended to dress in odd ways; they had unusual dietary and sanitary laws and strange religious ceremonies. If, for example, you were a Polish Catholic, you would look at a Jew and say, “This guy isn’t one of us. He’s certainly not Polish. He doesn’t even speak Polish. He doesn’t believe in the true Church. I can’t count on him to be on my side in hard times, the way I can count on my fellow Polacks. I wish he would go someplace else.”
At the same time, Islam was spreading all over the Orient, and for a while it looked like Islam would dominate Europe, too. Islam calls for the annihilation of the Jews. It’s in the Koran. That’s why I believe it’s always a mistake to hope for “peaceful coexistence” in the Middle East. The best that civilized people can hope for, is that the militant Islamic forces will be neutralized, and rendered hors de combat. Many individual Muslims are fine people, but Islam is a horrible religion that must be guarded against.
Gradually, the Jews blended into European society a little better, and were somewhat more accepted in Poland, the Holy Roman Empire, the Habsburg Empire, Great Britain, and elsewhere. They weren’t generally liked, but they weren’t harassed or killed. They were still unpopular—mostly for the reasons already cited, but now, also, because they had prospered.
Their unpopularity was due in large part to the Jews’ commonly held belief that it was their duty to improve society at large. Catholics, and some Protestants, generally focus on their own salvation and the welfare of their immediate families. Jews, however, tend to be more concerned with curing societal ills and “changing the world.” That’s why Jews tend to be “liberal” and “progressive,” and that’s where we get the stereotype of the “pushy Jew” who is always trying to mind your business and impose his values on you. It’s why so many feminists, Communists, and “professional malcontents” are Jews.
It’s also generally believed that most of the societal “improvements” that liberal Jews are always pushing, invariably benefit Jews in the long run. It’s commonly suspected that the underlying question is not, “How will this benefit society?” but “How will this benefit the Jews?” Stereotypically, the Jew’s commitment to society is regarded as less important than his commitment to the Jews.
Another huge factor that leads to generalized hatred of Jews is envy. Wherever they have gone, at least for the past few centuries, Jews in general have excelled and prospered. They contribute to whatever society they find themselves in. They tend to be generous givers to charity. They’re responsible for a remarkably long list of useful inventions and scientific discoveries. They’re high achievers in academia, finance, the hard sciences, and the arts. By just about any metric, Jews are the most civilized ethnic group in the world, and arguably the most ethical. This leads to generalized mistrust and dislike of Jews, for the same reason the “model” boy or girl in any school is going to be despised by many of his or her classmates.
Leftists hate Jews because leftism is driven by envy and covetousness. The worst outrages against Jews invariably come from the Left. (Nazism was a leftist movement: never mind the revisionist narrative.) The Left includes a lot of secular Jews, like Bernie Sanders, who are ashamed of their Judaism and despise religious Jews. Leftist governments, political factions, and individuals, all hate Jews because Jews win too much! Leftism is based on a generalized hatred of the Better. Jews in general are perceived as more civilized and more successful than most other peoples. The Left insists that the only explanation for this is that the Jews must have cheated.
This is why the American intelligentsia (including a great many secular Jews) have lined up on the side of Hamas and Hezbollah, since October 7. These people have always hated Israel, but the hatred has become more manifest in the past six months. Why does the Left hate Israel? Because Israelis are more civilized than the Palestinians. Israel is more advanced, more prosperous. It’s a principle with the Left to always root for the less civilized side! It can’t be that Israel is more successful because Israel is the superior civilization. It must be because Israel is an “oppressor state.” It must be because Israel is unfairly advantaged, and/or has played dirty pool.
I might be over-simplifying, but that’s the basic explanation.