"Jews in general do not believe that Jesus actually existed!"
Bullshit! One example of the many, many, many bits of bullshit produced by New Atheists and mythicists (people who doubt whether Jesus ever existed).
I myself am a mythicist: I'm not sure whether or not Jesus existed. I don't think there's anything wrong with investigating whether or not Jesus existed. Furthermore, I think that mainstream academic Biblical scholars are much too closed-minded to the possibility that Jesus never existed. But most of the most-prominent mythicists today are going about their historical investigations in a hopelessly inept way.
And the one follows from the other: when the pros, in this case the mainstream academics, refuse to investigate a very interesting question and declare that the case is closed when it's not, that leaves the amateurs, and that leads to predictably amateurish results.
And in this case it reinforces the theory that New Atheists and mythicists are predominantly ex-fundamentalist Christians, and hicks: if they'd ever MET any Jews and/or read some books written by Jews, both of which urbane and cultured Goyim are wont to do from time to time, the subject of Jewish attitudes toward Jesus would have naturally come up at some time or another.
I think it's easy to see where these doofuses could have made this mistake: it's not clear whether or not Hebrew writings from the early centuries mention Jesus. Jesus (Joshua) is a very common name, it's not crystal-clear whether or not one of the mentions of a Jesus/Joshua in these ancient Hebrew texts refers to the same person the Christians have in mind. Now add a huge confirmation bias on the part of the mythicists, and you're ready to make the premature leap from their being no mention of Jesus in those writings, to Jews believing that he never existed. Especially if you also completely ignore things like the Papal bull of 1554 which ordered all references to Jesus to be removed from the Talmud and other Jewish historical texts.
Another possibility is the huge premature leap from over-eager mythicists hearing that Jews reject the claim that Jesus was the Messiah, to hearing what they want to hear, in this case: that Jews reject Jesus' historicty altogether.
I'm sure that there are some Jews who don't believe Jesus existed. I wonder how many of them first got that notion from the same mythicists who are now triumphantly exhibiting them as alleged proof that Jews in general don't believe Jesus existed.