Many who do what today? They oppose Christianity? They become Christians? Learn proper diction?
Before the crucifixion of Jesus (even if such a person existed), it can be strongly argued that there was no "Christianity" to be opposed to. The followers of Jesus considered themselves Jewish apparently. And the fact that a handful of skeptics changed their minds over the course of their lives does not in itself prove very much. Perhaps they were gullible later in life? Perhaps their lives were threatened if they didn't comply? Perhaps they were easily swayed. And just because they convinced themselves to believe in Jesus proves nothing about the existence of God. Jesus himself might have been delusional enough to sincerely believe he was the son of god, but if someone said that today, we'd lock him up in an insane asylum. What makes Jesus less delusional than any other "son of god"? Getting more people to believe in your delusion, I suppose.