Judeo-Christian is a bizarre and problematic phrase for a number of reasons, but all of them fall under one initial blanket statement: Jews and Christians fundamentally disagree about everything.

I'm going to dig into this a little bit but first I would like to say that I will tolerate absolutely no antisemitism or buffoonery in the comments of this thread. I don't care what your personal opinion of Jews is or what you think about Judaism from an ideological standpoint, or even what you think about Israeli current affairs. This is not the time or place for that.

So first off is the big one: Jews don't think Jesus is the messiah. They don't think he's even of any relevance. They don't think he's a prophet, they don't think he's anything. Jesus is to the Jews what Joseph Smith is to Christians: a nut-job. Furthermore, Jews don't reckon with any of the events of the New Testament, least of all Jesus.

Christians boiled down all of Jewish religious text, the Torah, and called it their Old Testament. Christians don't even acknowledge 90% of it either, they just slapped their label on it and called it backstory. So much of the New Testament directly conflicts with the Torah that honestly it's hard to believe any of the writers of the New Testament read the Torah to begin with. No Jewish people acknowledge Christianity as a religion with Jewish origins because none of Jesus's acts fulfilled the prophecies laid out in the Torah. To call Christianity and Judaism by the collective Judeo-Christian is pretty insulting to Jewish people because Christianity has really nothing to do with Judaism at all.

Secondly: Judeo-Christian ignores that Christians have been killing Jews for centuries. The Holocaust? Spanish Inquisition? The majority of antisemitic hate crimes? All Christians doing that. A large percentage of Christians think Jews killed Jesus. Christians also created our most beloved antisemitic conspiracies and myths, like that Jews kill babies and drink their blood for arcane rituals, or that secret cabals of Jews conspire to control the world, or that Jews control all the banks because they're naturally greedy little gremlins. Hell, even the typical caricature of some monsters and villains are straight up antisemitic stereotypes. Why do you think witches always have crook noses and dark hair? Those are Jews. Tolkien's dwarves are a diasporic group who want to reclaim their homeland purely for material gain becasue they're Jewish stereotypes. J.K. Rowling's house elves are a race of slaves with large crooked noses and an obsession with money. Again, Jewish stereotype. Christians kill Jews all the time, and when they're not killing Jews they're demonizing them.

Thirdly: Ideologically, the two religions are nothing alike. Most sects of Judaism state that claiming to know beyond doubt that God exists is akin to blasphemy because you're claiming to have Godly knowledge. Doesn't sound very similar to the Christianity I know. Jews don't believe in Hell. Hell is a central pillar of Christianity. Judaism forbids evangelicalism. Under Judaism you are not supposed to bring your personal religion into someone else's home or nation with intent to convert them. Doesn't sound like the Christianity I know. I could go on, but I really don't feel it's necessary.

In conclusion, saying Judeo-Christian just communicates that you know nothing about how those two religions interact. The phrase has no place in conversation because it makes no sense. I truly have no idea where that word came from, but it has absolutely no value beyond creating cognitive discord.