How do people believe that a man who we have no evidence for existing is the prodigal human?

i dont understand christian theology in this respect? how can a man that history cannot even pin down as existing be the prodigal human? i mean i dont understand this reverence of jesus considering according to the bible he didn't make a huge sacrifice considering he got his life right back... he didn't give up anything in this sacrifice... he wasn't all of that nice of a person, he told his followers to sell their clothes and buy swords... he drove a villages pigs off a cliff(wasted all of their food)... like i could understand calling him a person but the perfect person? no not by a long shot...