I feel like it's an underappreciated point that Christians have never followed Jesus; they follow Paul. "Christian" has always been a marketing term for an imperialist, non-Jewish (and in fact, anti-Jewish) religion that took over the momentum of a small Jewish sect that died out once it became clear Jesus wasn't coming back.
Point of order; it took a few centuries to really get the anti-Jewish swing in progress. If it had been in full swing earlier on, there’d be no old testament.
The fact that Paul was a Jewish Gnostic is just - bonus.
After leaving the church, I've always found Saul/Paul's conversion story a bit suspect. So you mean to tell me that you're just out on the road one day, going from town to town persecuting Jesus-cultists, and a beam of light from heaven strikes you and tell you that what you actually need to do is join the Jesus-cultists, but spend the rest of your life assiduously walking back every radical thing they believe? Suuuure. I think maybe ol' Saul just saw a movement with a power vacuum at the top and thought he should be one to fill it.
Well the character “Jesus” is so clearly a continuation / rewrite of solar deity characters I think Paul must have had some task to “sell” it, but who/why/how I can’t speculate.