As we sit down to celebrate the birth of Jesus the Christ of Nazareth, it only be appropriate to look into the actual historical authenticity of this widely celebrated story whose only source is the New Testament

For starters, there are two nativity stories in the New Testament, one in Matthew and one in Luke and neither story is believed to have any historicity at all. The two stories are not even compatible with each other. They are set ten years apart with different, contradictory details and no real overlap.

In the view of mainstream scholarship, the Nativity stories were both independently invented by their authors as a means of getting Jesus born in Bethlehem in order to fit expectations and counter the perceived problem that he was from Galilee.

There are a number of details in each story which are either demonstrably ahistorical or highly implausible. Some problems with Luke, for example, include the fact that Augustus never ordered a census of the world, nobody ever had to travel to their ancestral towns to register for any Roman census and the census of Quirinius in 6-7 CE did not apply to Galilee and would not have applied to Joseph. Problems with Matthew are: Herod killing all the babies in Bethlehem (almost certainly never happened), the obviously mythological nature of the star and the magi, the angels and flight to Egypt, etc.

As I stated above, the stories also contradict each other. Matthew has Mary and Joseph starting out living in a house in Bethlehem, then has them flee to Egypt and then decide to relocate to Galilee only after they see that Herod's son, Archelaeus, has become Tetrarch of Judea. Luke has them starting out in Nazareth, only going to Bethlehem for the census, then going right back to Nazareth after presenting Jesus at the Temple. Their genealogies contradict. The census of Quirinius didn't happen until ten years after Herod died. Luke has no Magi, slaughter of innocents or flight to Egypt; Matthew has no census, no inn, no shepherds in the fields or singing angels. If you read the two stories together, you will see that they are not two different versions of the same story, but two completely different stories.

Matthew was trying to draw mythological parallels of Jesus to Moses. Luke was trying to ground Jesus' birth in some kind of pseudo-historical context. Neither story is believed to be historical in any degree at all. It is generally believed by critical scholars that Jesus was born in Galilee, that this was seen as a problem because the Messiah was expected to be born in the same town that David was born, and the nativity stories were invented as independent attempts to solve that problem.

If you want to educate yourself further, the definitive book on this is probably Raymond Brown's Birth of the Messiah, but these same main points are reiterated in pretty much any academic assessment you would find. John Crossan's Historical Jesus is another one that really goes into this in detail.