Jesus in History – Historicity of Jesus
Jesus in History or Historicity of Jesus is one of the most essential topics because if Jesus didn’t ever exist, Christianity has no reason to exist, has no root and no purpose. Virtually all modern scholars of antiquity agree that Jesus existed, and most biblical scholars and classical historians see the theories of his non-existence as effectively refuted. In antiquity, the existence of Jesus was never denied by those who opposed Christianity. Regardless of the scholarly disagreements on the reconstruction of portraits of the historical Jesus, almost all modern scholars consider the baptism of Jesus and his crucifixion to be two historically certain facts about Him. James Dunn states that these “two facts in the life of Jesus command almost universal assent” and “rank so high on the ‘almost impossible to doubt or deny’ scale of historical facts” that they are often the starting points for the study of the historical Jesus.
Non-Christian Sources (they testify about the historicity of Jesus, about the reality of His existence):
1.Josephus Flavius about Jesus
The writings of the 1st century Romano-Jewish historian Flavius Josephus include references to Jesus and the origins of Christianity. Josephus’ Antiquities of the Jews, written around 93–94 AD, includes two references to Jesus in Books 18 and 20.
Of the two passages the James passage in Book 20 is used by scholars to support the existence of Jesus, the Testimonium Flavianum in Book 18 his crucifixion. Josephus’ James passage not only attests to the existence of Jesus as a historical person but that some of his contemporaries considered him the Messiah.
The passage deals with the death of “James the brother of Jesus” in Jerusalem, and given that works of Josephus refer to at least twenty different people with the name Jesus, Josephus clarifies that this Jesus was the one “who was called Christ”.
The overwhelming majority of modern scholars consider the reference in Book 20, Chapter 9, 1 of the Antiquities to “the brother of Jesus, who was called Christ, whose name was James” to be authentic and to have the highest level of authenticity among the references of Josephus to Christianity. Louis Feldman states that the authenticity of the Josephus passage on James has been “almost universally acknowledged”.
2.Tacitus about Jesus
The Roman historian and senator Tacitus referred to the crucifixion of Jesus by Pontius Pilate and the existence of early Christians in Rome in his final work, Annals (written ca. 116 AD), book 15, chapter 44, in the context of the persecution of Christians and the Great Fire of Rome. Scholars generally consider Tacitus’s reference to the execution of Jesus by Pontius Pilate to be both authentic, and of historical value as an independent Roman source about early Christianity that is in unison with other historical records.
Tacitus was a patriotic Roman senator and his writings shows no sympathy towards Christians. Andreas Köstenberger and separately Robert E. Van Voorst state that the tone of the passage towards Christians is far too negative to have been authored by a Christian scribe – a conclusion shared by John P. Meier.
You can read some more interesting details also on the wikipedia page about the historicity of Jesus.