Hebrews were not a racial cult until Ezra turned it into one, traced through the mother, in order to exclude sharing power with other Jews who weren't exiled or were living elsewhere. Oer the next few centuries they developed quite an extensive set of 'racial purity' codes and laws; they were using their influence with the Persian to set themselves up as the local govt. and and masters of the 2nd Temple and all the power and wealth that produces. Other Jews were 'tainted' in the regimes that followed. It is why genealogies were so important; they didn't want the local Jews sharing in the spoils with them. The whole idea of a 'Hebrew Nobility' was an alien idea until Samuel, and then it was only an emergency need for the current political climate and outside enemies. It was also part of the beginning of the decline of the Hebrewism of Moses.
They persecuted a lot of them, especially the Samaritans and Galileans as well as many in the Diaspora as it then existed, along with the Christians; they attempted to wipe out Christians for centuries, joining their Muslim buddies when they came along, providing soldiers and administrators for the conquests. They've invented an extensive fake history for themselves as hapless innocent victims of Evul Xian Bigotry N Stuff for centuries as well, to cover up why they were so discriminated against and why they were never trusted in the Western European kingdoms.
Currently they have a lot of Christians hoodwinked into beleiving they're the Jews of the Covenants, but in real life those Jews died with the Babylonian conquest, no Prophets since about 400 B.C. at the latest is evidence of that, and the degradation of the culture into racial minutiae and silly legalisms like the fictional 'Oral Torahs' and all that followed. around 300 B.C. Jewish intellectuals, many of then anyway, embraced Greek philosophies and some Gnostic cults began forming, the Pharissees rise to influence, leading to the chaos the Christian sect was formed from, along what others like the Siccari of Masada fame, Essenes, and Mandeans, etc. That the short answer, without the 3,000 page exegesis of some 500 year timeline. The Rabbinical cult and Talmud focus are 2nd Century and afterward; the Christian Jewish sect is almost a 100 years older than 'Orthodox' Judaism, and by the far the most influential and successful one, with a more advanced and intellectual theology and social framework.