And Joseph also went up from Galilee, from the city of Nazareth, to Judea, to the city of David, which is called Bethlehem, because he was of the house and lineage of David, to be enrolled with Mary, his betrothed, who was with child. And while they were there, the time came for her to be delivered. And she gave birth to her first-born son and wrapped him in swaddling cloths, and laid him in a manger, because there was no place for them in the inn." (Luke 2:4-7)

According to this passage, Jesus' parents were from Nazareth, but traveled to Bethlehem in order to be counted in a census; this leads to Jesus being born in a manger in Bethlehem, rather than his parent's native home in Nazareth. In the book of Matthew, Jesus is also born in Bethlehem. But his parents are said to have been from Bethlehem. And he isn't born in a manger, much less a cave. (Matthew 1:18-2:12)

The contradictions in the accounts and their unreliability -- there is, for instance, little historical evidence of a census being taken at the time, as Luke states -- have led many scholars to believe that Jesus may not have been born in Bethlehem at all, a belief that would effectively devalue the significance of the Church of the Nativity.

According to Robin Lane Fox, the discrepancies can easily be explained."Early Christian tradition," he says,"did not remember, or perhaps ever know, exactly where and when Jesus had been born." What was important, Fox suggests, was that Jesus be identified with Bethlehem because in the Old Testament it was prophesied that the messiah would be descended from David and David was from Bethlehem.

Where was Jesus actually born? Probably in Nazareth. He is often referred to as"Jesus of Nazareth," and it was naming convention at that time to call someone by the town where one was born, if not by the name of the father. So if Jesus was indeed born in Nazareth, or possibly in another Bethlehem (in Galilee) as some suggest, then the Church of Nativity may be nothing more than a church built on top of an unimportant cave.

The actual birthplace of Jesus is of no real consequence to the Christian faith; whether born in Bethlehem in a manger or in a house in Nazareth, the emphasis of the Christian church is on Jesus' life, death, and resurrection.

SOURCE

Robin Lane Fox, The Unauthorized Version (New York: Alfred A. Knopf, Inc. 1991).

"The Search for Jesus" (beliefnet.com).