When was Jesus born? We don’t know. Only two of the Gospels say anything about this. None of the other New Testament books mention it. Either it wasn’t thought noteworthy, or no one had any idea, or both. Jesus was a Jew, and so were his earliest followers. As well as finding ‘evidence’ for Jesus as the promised Jewish Messiah, being a historical figure, it seemed profitable to correlate suitable historical events with his birth.
A key character in Matthew’s story is Herod the Great (in his own eyes anyway). Herod died in 4 BCE and so, if Matthew’s account of his order “to kill all the children in Bethlehem and throughout the surrounding region from the age of two and under” has any historical basis, Jesus was born around 5 BCE, give or take.
( We should note, in passing, that a monk called Dionysius Exiguus (Little Dennis) thought Jesus had been born in year 1 of what he called AD, anno Domini, the ‘year of the Lord’. There wasn’t a year 0, because a numerical zero didn’t appear until the 6th century – this troublesome fact causing the dispute about whether the new millennium began in 2000 or 2001. Little Dennis must have had a big laugh! )
To return to 5 BCE, why December 25th? More precise would be, why was this date chosen? The earliest reference to dates doesn’t come until around 200, when Clement of Alexandria mentioned 20th/21st April, or 20th May, but not December ! It’s not until the mid-4th century that a Roman almanac marks December 25th as “natus Christus in Betleem Judeae” – ‘the birth of Christ in Bethlehem of Judea’. But why?
One suggested reason has to do with late December’s Midwinter Solstice. The ‘dying’ Sun, reaching its lowest point in the sky, as if reborn, begins to ‘rise again’ in promise of summer’s eventual return. In 274, Emperor Aurelian established, on 25th December, the feast of the birth of “Sol Invictus”, the unconquered Sun. It may be that high-jacking that feast for an alternative (and side-tracking) Christian celebration of the birth of ‘the unconquered Son’ was just too tempting to resist.
Another suggested reason involves the Christian theologian Tertullian, around 200, fixing the date of Jesus’ crucifixion as March 25th. Following on from that, is a 4th century Christian treatise which says, “our Lord was conceived on March 25th, which is the day of the Passion of the Lord and of his conception. For on the day he was conceived, on the same day he suffered”. If Jesus was conceived on March 25th, then fast forward 9 months, and we get December 25th for his birth.
Picking either of these, or none, makes no difference. December 25th it is, has been, and ever will be, world without end. Whatever our religious beliefs, let’s enjoy, not the worst, but the best of what it has to offer, as a moment of promising brightness in the cold darkness of winter.