text: We do have some extra-bibical mention of Jesus from, if memory serves, Tacitus and Josephus. But the main sources are the gospels, which can be used for historical purposes, even if that is reading against the grain. Pontius Pilate and Herod are known historical figures, who are described in other sources much as they appear in the gospels. The genre of the gospels has been a much discussed topic, but to me they seem to represent ancient historiography. They present narraives with thier own theological purposes, but all agree in Jesus being the Baptist's disciple, on the shared perception of his ministry, on his death. .  Which does not validate everything they say by any stretch of imagination. Some are clearly created without any concern for historical facts, like the disciples picking grain on the sabbath, while others are more rooted in the history we do know about Second temple Judaism. Analoguously, if we cannot rely on Buddhist scriptures, we would not know if he ever existed.