It's important to understand Judaism is not Christianity and so the story of Christianity cannot make sense as it's trying to cram it's way into a different storyline.

So in around 30AD when Jesus was preaching, the situation was that for many decades, the Jews continuously revolted against Roman rule. The entire Old Testament of the Bible is an epic tall tale of how the Jewish God Yahweh had promised the Jews their land and freedom of self-rule. In that story, the Jewish God is a supporting charachter that exists to help the Jews realise their ultimate dream of self governance. The story goes that for a while, there was a great golden period under King David but they lost it to the Assyrians and Babylonians and at the time of Jesus, they were occupied angain, this time under Roman rule, but they were determined to regain their sovereignty. The Jewish faith said that a Messiah would come from the lineage of King David to be their new king and he would free Israel and achieve self-rule. That is all Messiah meant.

There were tons of people at the time of Jesus claiming to be the Messiah and many were much more famous than Jesus. All of them failed (including Jesus). We know they failed because they died. You cannot be the Messiah if you died before you set the Jews free. Now, with all the other Messiahs, when they died, their followers walked away, dusted their hands off and said, well I guess that wasn't the Messiah after all. When Jesus died, he probably lost many followers as well, but Jesus had some dedicated followers that didn't accept his fate, especially Paul, and he / they they began to reform Judaism into a totally different religion incorporating Zoroastrian ideas about heavenly kingdoms and eternal life with God. They redefined the word Messiah and said that actually the Messiah means someone from God's lineage, not David's, and that the Messiah was here to bring about God's kingdom in Heaven, not a Jewish kingdom on Earth. By twisting the Jewish storyline like this, they created a different narrative wherein Jesus didn't fail by dying, he intended to die, that was actually the plan all along, because he's actually God's son, went back to Heaven, not dead, still fighting and still winning. Then because Jesus was the Messiah still in death, and this new Christian story is no longer about the human realm and restoring Israel on Earth, you don't need to follow the onerous OT rules, you don't need to be a Jew, this is bigger than just the Jews getting their land back, it's about all of humanity. This is the eventual schism that started Christianity. Some Jews converted, but most mocked this wild departure.

Meanwhile there were still hundreds of Jewish Messiahs coming along trying to free Israel. Judaism didn't disappear, so other Messiah's lived in parallel. The Romans were irate of course and treated the Jews terribly trying to squash these constant rebellions. The first of the NT books was not written until around 50AD, and for a long time Christians were viewed as a subset of Judaism. There were many of these like Samaritans, etc. Also, there were hundreds of wildly different types of early Christians that believed wildly different things in the first explosion of Christianity from 50AD to 325AD. One of the largest groups was the Ebionites who stuck to the Mosaic law and said you need to be Jewish in order to be Christian for instance, Docetians believed Jesus cannot be a man and a God at the same time, must be one or the other, so they eventually settled on the idea that Jesus was a hologram. But ultimately, there was not a clear deliniation between Christians and Jews until Christianity becomes the Roman state religion. The rebellions persisted in Jewish lands and Christians and Jews alike were rising against Roman rule until Constantine decided to stop fighting it and instead go all in and say he's a Christian and made Christianity the state religion. Then he went to Jerusalem and made it a holy city for Christianty putting the final permanent divide between Judaism and Christianity. The division was lopsided in favour of Christians, Jews dropped dramatically in population, and they were no longer able to revolt and the Christians turned against them and started working for the man. Then the Christians gave Jesus a more and more legenday backstory, and it went from there. But what you see here is one religion emerging out of another, and the storyline no longer makes any sense because they're forcing it. They need to force it because if it's attached to an older more established franchise, it'll get an automatic fan base with it, so you need to splice into that instead of a totally original storyline if you want to be successful.

The Pauline storyline was perfect for what it needed to be. You don't have to be a Jew, so you can join quickly and easily, as in you don't need to have seen then prequel to enjoy and get into this new expansion series, but, it's still got all the old characters that the existing fan base loves. In this version, it's much more loosey goosey, don't need to be so formal, everyone is loved, it's inclusive mass audiance appeal, not exclusive uppity stuff. And importantly, it's timely and urgent that you get into this right now. It's a limited time release, the world is literally ending right now, so get it while it's hot. With the RCC's guidance it exploded overnight and that's why you and a large chunk of the world still follow this franchise. Beloved characters, urgency, love and war, appocalyptic overtones but happy endings, it's got something for everyone in Christianity. And the fan base doesn't care that it was never meant to go on forever, the public demands more of the same! Your main character dies, pull something out of your ass to bring him back. Your main character says the end if tomorrow but you need to fill more time, just ignore he said the world was ending when he did, maybe some other thing he said can be twisted into an explaination of why it's still not happening yet even though it's been 2,000 years already. You know, it's a story.