Is it solely because of the supernatural claims made (his miracles and resurrection) that people dismiss his existence in history? We have no contemporary writings on Cleopatra, only greco-roman scholars and historians, yet I don't think anyone will claim she didn't exist. There are non-biblical historians who mention him or his followers and even attest to him being crucified under Pilate's rule. The gospel writings are written between 20-40 years after his death. That would be no different then someone who was close with Martin Luther King Jr and decided today to write all about their times and life with him before his death. I don't see how you find this ridiculous. There are very few historians that say he never existed. They acknowledge he existed and dead by crucifixion under Pilate's rule. Enemies of the Christians acknowledged his existence and even showed their disdain for Christians and what they thought of them.
Lucian a second century Romano-Syrian satirist and a pagan who lived during the second century also wrote in his book "Philopseudes", nn. 13, 16; "De Morte Pere that “The Christians, you know, worship a man to this day — the distinguished personage who introduced their novel rites, and was crucified on that account… You see, these misguided creatures start with the general conviction that they are immortal for all time, which explains the contempt of death and voluntary self-devotion which are so common among them…”
Tacitus the Roman historian who lived between A.D. 54 and AD. 119 also wrote in his book ‘Annals XV, xliv’ that Jesus was put to death by Pontius Pilate. Suetonius, who was another Roman historian and lived from AD 75 to AD 160 similarly mentioned the crucifixion of Jesus. Pliny the Younger (AD 61- AD 115) wrote a letter to the Roman Emperor Trajan in which he confirmed the crucifixion of Jesus. Other pagan writers who acknowledged the crucifixion of Jesus are Numenius, Galerius, Phlegon and Celsus. These pagan writers did not believe in the sacrificial and redeeming death of Jesus on the cross. Indeed, some of them even laughed at this earth-shattering incident, but in writing and making fun of Christianity they have contributed to a preservation of historical records that provide ample testimony that Jesus was indeed a historical person, was crucified and died
Lucian a second century Romano-Syrian satirist and a pagan who lived during the second century also wrote in his book "Philopseudes", nn. 13, 16; "De Morte Pere that “The Christians, you know, worship a man to this day — the distinguished personage who introduced their novel rites, and was crucified on that account… You see, these misguided creatures start with the general conviction that they are immortal for all time, which explains the contempt of death and voluntary self-devotion which are so common among them…”
Tacitus the Roman historian who lived between A.D. 54 and AD. 119 also wrote in his book ‘Annals XV, xliv’ that Jesus was put to death by Pontius Pilate. Suetonius, who was another Roman historian and lived from AD 75 to AD 160 similarly mentioned the crucifixion of Jesus. Pliny the Younger (AD 61- AD 115) wrote a letter to the Roman Emperor Trajan in which he confirmed the crucifixion of Jesus. Other pagan writers who acknowledged the crucifixion of Jesus are Numenius, Galerius, Phlegon and Celsus. These pagan writers did not believe in the sacrificial and redeeming death of Jesus on the cross. Indeed, some of them even laughed at this earth-shattering incident, but in writing and making fun of Christianity they have contributed to a preservation of historical records that provide ample testimony that Jesus was indeed a historical person, was crucified and died
We are not made happy by what we acquire but by what we appreciate.