I sometimes debate online with atheists and agnostics who sincerely believe that Jesus never existed. I post this summary of a recent article, linked at the foot of this posting, for the benefit of them and any other spiritual seekers.
Firstly, recent archaeological finds reveal that Nazareth existed and was settled in the time of Jesus.
Furthermore, Jews in the time of Jesus believed that there would be a messiah figure who would suffer and die, that Christians always believed in Jesus as being divine, and this was not a later innovation.
The gospels were based on written sources, and not oral transmission, as skeptical New Testament scholars have claimed.
The gospel of Mark, widely believed to be first of the gospels to be written, may have been written 5 to 10 years after Jesus was crucified, and not in the late 60s or early 70s AD as scholars often claim.
Finally, many contemporary authors claim that Jesus was an illiterate peasant. However, looking at the debates between Jesus and the Pharisees in the gospels, Jesus shows a thorough knowledge of Jewish law and scripture.