I've always wondered why people were so ready to convert. Like, if I was some ancient Roman and some guy came up to me offering a new god that's even better than the old ones and much easier to worship, I wouldn't just immediately fall for it. It just seems like a scam.
It did take a while, and I'm sure people called it a cult of Jesus or something back then too (Idk if there's evidence for that but there were many cults of Gods/demigods etc. in antiquity)