The historical evidence for Jesus of Nazareth is both long-established and widespread. Within a few decades of his supposed lifetime, he is mentioned by Jewish and Roman historians, as well as by dozens of Christian writings.
The first Christian writings to talk about Jesus are the epistles of St Paul, and scholars agree that the earliest of these letters were written within 25 years of Jesuss death at the very latest, while the detailed biographical accounts of Jesus in the New Testament gospels date from around 40 years after he died. These all appeared within the lifetimes of numerous eyewitnesses, and provide descriptions that comport with the culture and geography of first-century Palestine...
we have the Roman politicians Pliny and Tacitus, who held some of the highest offices of state at the beginning of the second century AD. From Tacitus we learn that Jesus was executed while Pontius Pilate was the Roman prefect in charge of Judaea (AD26-36) and Tiberius was emperor (AD14-37) reports that fit with the timeframe of the gospels....
About 10 years ago, The Jesus Project was set up in the US; one of its main questions for discussion was that of whether or not Jesus existed. Some authors have even argued that Jesus of Nazareth was doubly non-existent, contending that both Jesus and Nazareth are Christian inventions. It is worth noting, though, that the two mainstream historians who have written most against these hyperskeptical arguments are atheists
https://www.theguardian.com/world/2017/apr/14/what-is-the-historical-evidence-that-jesus-christ-lived-and-died