As I have summarized in publications, once the Roman Empire formally adopted Christianity as its official religion in 380 CE, older spiritual systems with their multiple deities were suppressed. The new story was then progressively amended over many decades to broaden its appeal in pagan societies.
And the church, which came under government control, eventually elevated Jesus to the second deity of the tripartite Christian godhead. Yet most are unaware that early Jewish followers did not view Jesus as God or part of a Trinity. Rather, they saw him as an exalted, wise Prophet with great, priestly spiritual authority whose teachings presented re-incarnation as a given.
This belief would persist for over five hundred years, causing serious concerns for central government. And Roman fears were well-founded in that it is nearly impossible to control people who lack any fear of suffering or death. Eventually, the Church would formally disavow reincarnation. And it would cast it onto a growing heap of newly identified heresies.
Over the years, the late Glenn Kimball summarized some of the historical evidence regarding the physical existence of Jesus the man. And he showed how much of what we've been taught is wrong.
Apologies to you or anyone who might be offended by this very non-PC narrative.