Was Jesus, the historical person ever alive? What are the historical evidence to prove that?

Before going into answering the question, first we should determine what do we mean by “historical evidence”. By historical evidence we mean the evidence available for past events or persons which can be verified to a certain degree of reliability. For establishing this one has to answer certain questions: When was the manuscript or artifact made? Is the author of the written document reliable? What is the context in which the artifact or the written document existed? Is the discovery of the artifact or written document reliable? By answering these questions one can finally conclude whether or not to accept the evidence presented to him. 

The next step would be to look into the sources through which we come to know about Jesus which would include written documents such as the Gospels and secular works written by Josephus, Tacitus, Pliny the Younger etc. If we take the Gospels, one might question the intentions behind presenting them as being historical evidence. But the simple truth is that the Gospels, when critically analysed using the questions presented earlier, turns out to be fit to be taken as evidence for the historicity of Jesus. They were written mere decades removed from the time of Jesus and the earliest manuscripts we have dates back to the first half of the second century. One might think that these are far removed but we have to keep in mind that for all works of classical antiquity we will have to depend on manuscripts that were written long after their original composition. To bring matters into context, the earliest manuscripts of works by Virgil where written 350 years after his death and as for Plato it is 1300 years! Yet no one disputes their existence or the accuracy of the work. 

This is one of the reasons why the Catholic Church makes the following statement: The Church holds firmly that the four Gospels, whose historicity she unhesitatingly affirms, faithfully hand on what Jesus, the Son of God, while he lived among men, really did and taught for their eternal salvation, until the day when he was taken up. (CCC 126)

As for Josephus, he was a Jewish historian who served in the Roman emperor’s court in the first century, he is known to have written a history of the Jewish people called the Antiquities of the Jews. In this work he mentions about James as being the brother of a person called Jesus, who was also called Christ. In another section, which is called Testimonium Flavianum, he again mentions about Jesus as being a wise man who did startling deeds, who was later crucified and that his followers were called as Christians. 

Tacitus on the other hand was a Roman historian who in his work the Annals writes about Emperor Nero who blamed the Christians for the great fire that engulfed Rome in 64 AD. He notes that the name “Christians” came from their founder who was called “Christus” and that this person was put to death by Pontius Pilate, procurator of Judea in the reign of Tiberius.

Gaius Plinius Caecilius Secundus otherwise known as Pliny the Younger, was a Roman author and administrator who has written several letters that depict the Roman culture and lifestyle. In one of these letters, written in 112 AD, we find him mentioning about Christians as follows: “they were accustomed to meet on a fixed day before dawn and sing responsively a hymn to Christ as to a god.”I am sure that this relatively short answer by no means covers all the evidence that we have regarding Christ. Therefore I urge you to continue your truth seeking and one starting point could be the book called The Case for Jesus: The Biblical and Historical Evidence for Christ by Dr. Brant Pitre.