Reason Jesus must have been a real person

[robvalue]

The people who wrote about him didn't know whether it was a real person or not, based on the flimsy secondary information they had about him, if he existed at all. So we certainly can't know. At best we could say they intended to write about a real person. (They then either believed a load of magical events as part of that, or made it up themselves.)

Anyhow, his name wasn't Jesus either. That's a later change. The letter "j" wasn't used at the time. It was thought to have originally been written as something like Yeshua.