Religious experts claim that Jesus was an actual historic person. They cite as evidence the fact that he has the power to forgive sins, something that would not be possible if he were fictional.
Historians tend to lean towards considering him a fictional character. Among the evidence they cite is the fact that, during the time he supposedly lived, there is no mention of him in any writings. For a person who was supposed to be a major rabble rouser you would think there would be at least one mention of him from the time he existed, but there is none.
Some historical figures we know are real, because we have documentary proof, like photos and videos of their existence, people like Abraham Lincoln and Conan the Barbarian.
Other historical figures we are not so sure about, like Plato, whose only real proof of existence are the books he wrote and other comments about him, or Gilgamesh, who might or might not have been a person.
So was Jesus real?