Those are all valid points. Still, Christian Cosmology is the same as Jewish Cosmology: the world as an artifact created and ruled by a single all-knowing monarch who is in essence different and separate from it. And Jesus did define himself as coming to confirm the teachings of Judaism e.g. in Matthew 5:17, although in practice his teachings were very different - hence Christianity not being considered a Jewish sect but a separate religion. And because of this claim he made, the Jewish scriptures were received into Christianity, bringing along several beliefs that simply have nothing to do with anything Jesus ever thought was worth mentioning and several more which directly contradict his teachings. So there is of course this powerful connection between the two that can’t really be severed.
As for “multiple gods through the Trinity”, I wouldn’t put it like that exactly. Rather than being similar to Greco-Roman polytheism, the doctrine of the Trinity seems to me closer to the Hindu Trinity of the Godhead (Brahman, Vishnu and Shiva). Hinduism is of course polytheistic but these three gods in particular are not separate persons but different aspect of the same entity that manifest in different circumstances. A crude analogy would be if a person adopted one identity at work, another one at home with their family and another one while asleep. It’s still the same person, but fulfilling different roles. So it is with the Holy Trinity of Christianity. Hence what Paul said in Philippians 2:5-8:
In your relationships with one another, have the same mindset as Christ Jesus: Who, being in very nature God, did not consider equality with God something to be used to his own advantage; rather, he made himself nothing by taking the very nature of a servant, being made in human likeness. And being found in appearance as a man, he humbled himself by becoming obedient to death — even death on a cross!
In any case, this is a very interesting discussion.
I didn’t say that “Christianity” itself quotes the Old Testament for purposes of bigotry, but that the fact that some Christians do even when said bigotry contradicts Jesus’s teachings, which is indisputable, is proof that Judaism is indeed packaged into Christianity in a certain form. And the point of view under which it can be called Judaism for export is really quite simple: Judaism considers Hebrews to be the Chosen People and everyone else is just out of luck. At best, you can marry into the religion. Jesus comes along and in a manner of speaking opens up access to the Hebrew God for anyone willing to follow him, regardless of their bloodline. Hence Judaism for export. Christianity quite literally took several Jewish ideas, such as their creation myth, and packaged them with a new doctrine that allowed them to be exported to other peoples.
Let’s not throw around words like antisemitism with such carelessness. There is bigotry in the Old Testament, such as the infamous Leviticus 20:13. Mentioning this is neither an attack on an entire race of people nor an implication that bigotry is somehow exclusive to Judaism, which just for the record, it most certainly is not. I’m trying to have a good faith conversation comparing different belief systems, and I don’t have the filthy habit of judging a human being’s worth from their religion, or worse, from their ethnicity.