Actually, the best analogy is that it's either Fundamentalist Universalism or Judaism, no other. But yes, Catholicism/Orthodoxy is in a pickel because it preaches Judaism to the Protestants and Protestantism to the Jews.
Protestantism easily degenerates into Christ as fetish: as long as I say Jesus is my personal savior, I'm saved. No ethical observation or consideration is necessary on my part. Whereas, the Orthodox and Catholic believe in working out our salvation. God gave us salvation like paying off all our debts and giving us a million $$$. Do we then go into more debt and spend our inheritance like prodigals? I think not. What we are is God's gift to us, what we become is our gift to God.
If it 'tweren't broke, it didn't need fixin'. The Noachide Laws (for non-Jews) and Torah (for Jews) provide all that is necessary for making oneself a gift to G-d. It certainly wasn't necessary to come up with a whole new religion to do what was already being done.
“It certainly wasn’t necessary to come up with a whole new religion to do what was already being done.”
Well yes, maybe it was necessary. Because of Jesus Christ, who was Jewish, and had Jewish followers, no gentiles to speak of at this point, all Jewish, who believed him to be the Messiah. Therefore, those Jews believing Jesus Christ to be the prophesized Messiah differentiated themselves from their fellow Jews who didn’t believe Christ was the Messiah. At that point, the two different groups of Jews went their divergent ways in religious belief and traditions, which was inevitable, as the squabble over whether Christ was the Messiah or not was not going to be solved. Hence it was really an internecine battle between Jews that split apart. Hence “Christ”ianity, Jewish followers of Christ as versus Jews who did not acknowledge Christ as the Messiah. So if a “new religion” as you put it was created, it was created by Jews, those that believed the Messiah prophesized in the OT had arrived on earth. And the Jews that rejected it stuck with the old traditions that were not built around the idea of the actual coming of the Messiah, obviously. And the Jews that believed in Christ built their traditions around the fact that Christ was the Messiah. Obviously the Torah, by inference, and the Old Testament (written by Jews and a basic component of Christian religious belief) is included in the Christian religion, as the Messiah was prophesized, and the Christians surely believe that happened, don’t they.