Lol Some Jews don't believe. The Christians were nearly all Jews at the beginning, with Some Gentiles that were Jewish converts that attended the synagogues and Temple. Jesus was a reformer, and advocated a return to the original Mosaic Torah, as opposed to the Babylonian 'master race' nonsense of Ezra's 'reforms' and the obscurantist Pharisees and Temple nonsense. The rise of Christianity was as a Jewish sect, preached in the synagogues around the ME and the Empire until finally banned and violently persecuted by the Babylonian cultists.
One of the main reasons for including the Torah in the Christian Bible is to establish the Mosaic Torah back to its rightful place in the theology as a universal theology, not as a discarded antiquity as it was under the Babylonians' return, replaced by a lot of bizarre racist 'legal interpretations' that make up the Talmud and the Mishnas, all produced much later. Christianity is in fact older than Rabbinical Judaism by several decades.