- This is a bit of a theological question
- The facts of the matter are given on Wikipedia:Chronology_of_jesus
The only sources of information on Jesus' birth are the gospels of Matthew and Luke of the Bible.
Matthew describes King Herod as the ruler during the time of the Nativity, and Herod died in 4BC. Furthermore, in order to kill Jesus and eliminate him as a rival king, Herod orders the "Massacre of the Innocents" — the killing of all male children in Bethlehem aged two years and under. This means that Jesus may have been up to two years old already by that time, and this sets the Nativity at around 6BC.
Luke places the Nativity during the Census of Quirinius which took place in 6 AD, although Luke states the conception took place during the reign of King Herod - about 10 years earlier.
Because both Gospel accounts agree that the birth took place before the death of Herod, Jesus was born around 4 BC or slightly before.
- So what we have is that Jesus was born
- Scripture at that time records that it was a Virgin Birth
- The teaching of the Church in the New Testament, in the Gospels, the Acts of the Apostles, and the Letters of Paul, make it clear that Jesus is the Son of God, and God is his father.