Second thing Jews for Jesus doesn't want you to know: Jews for Jesus believes that God is three and not one.
The first principle of Judaism is that G-d is one and alone with no other serving as G-d as we say, “Hear O Israel the L-rd is our G-d, The L-rd is one” (Deuteronomy 6, 4). It is with this pure monotheism that Jews have opposed all pagan and multi-god beliefs that non-Jews believed. Many Jews sacrificed their lives for this belief in all generations; quite often by not acceding to Christianity, with its inquisition and crusaders. The foundation of faith believing in one G-d is what actually defines us as Jews since we became a nation and united us through every era and times.
Christians in contrast with us never believed that God is decidedly one. According to their faith the creator of the world is not one but three gods which they call the holy trinity. This triangle includes what they call “the father, the son and the holy spirit”. According to them god always was three gods combined. To them the father is the creator, the son is Jesus and the Holy Spirit is the god that impregnated the Virgin Mary in an “immaculate conception” and placed Jesus in her womb. The Christians pray to Jesus bless the people in the name of the “Father” and turn to the “Holy Spirit” in their prayers too.
If you speak to “Jews for Jesus” about this they will philosophize about the three parts composing one or a triangle made of three sides or that similar to water that has different properties, so too their three are really different properties of one so it’s all okay. They will also tell you that one in the Scriptures, echad really means three, (go figure!) and they will attempt to find convoluted proofs and hints from the scriptures to their pagan belief which for some reason eluded genuine Jews for millennia until the new testament came on the scene.
According to Judaism every Jew must sacrifice his life and not transgress believing in one G-d that is absolutely one and no more than one and not believe in a god made of three parts or three gods combined from “the father son and holy spirit”. Maimonides already ruled that Christians are considered pagan idol worshippers and prohibited drinking or even deriving benefit from their wines.
This strange faith that god is three is taken from the Catholic church that see Jesus as a god and not as a person. Both Messianic Jews and Jews for Jesus ascribe to this catholic belief and call themselves Jews only to ensnare other Jews in their missionary traps.
I cannot imagine a rational Jew that read the Torah that could still believe in this pagan belief.