How could anyone doubt that Jesus existed?
There exists very little evidence of the historical life of a man named Jesus Christ. There are no records of him in the Roman histories of that time.
Of course no one's ever found a body, either! THAT would turn the world on its head!
Jeez, I don't know. Its not as if the Bible or the Church had anything to gain by lying, right?!
Actually, he WAS a real historical figure. But he certainly wasn't a supernatural being.