Re: Jesus Christ, the founder of Christianity,
"Saul, who was a tax collector, heavily oppressed early Christians while Jesus was alive."
Which makes it somewhat difficult to believe that Christianity didn't exist before he founded it.
"...in order to build a book of mostly coherent religion that suits their needs to control people"
Another possible explanation is that most people are so insecure in their beliefs they need to recruit others into it. The greater the number who believe, the more likely the belief's true.