You probably know that Jesus' birth is used as the dividing point between BC and AD. BC stands for "Before Christ," and AD stands for Anno Domini, which means "Year of the Lord" in Latin. This dating system is based on the estimated year of Jesus' birth calculated by the theologian Dionysius Exiguus in 525 AD when he wrote the "Easter Table" at the Pope's request. For this reason, many people think Jesus was born at that time. However, this differs from actual history because Dionysius made some mistakes in his calculations.
The first mistake was creating a 1-year gap by having AD 1 follow directly after 1 BC, without a year zero. The second mistake was omitting 4 years from Emperor Octavian’s reign due to problems with the sources Dionysius used. For these reasons, our current dating system differs by about 5 years from Jesus' actual birth.
Because of these errors in what we commonly assume, let's try to estimate the timing of Jesus' birth by looking at actual history. The first clue for estimating Jesus' birth is the death of King Herod. Josephus' Antiquities of the Jews records an event from the year Herod died. Herod had erected a golden eagle statue at the temple entrance, which 40 Jews tore down. A lunar eclipse occurred on the night of this event, which is thought to be the eclipse of March 13, 4 BC. Based on this event, Herod's order to kill babies under 2 in Bethlehem, and other astronomical data, scholars estimate Jesus was born sometime between 7 BC and 4 BC.
This novel assumes 5 BC, though it could have been 7 BC, 6 BC, or 4 BC - saying we can't know for certain is probably the most accurate answer.
The second clue for estimating Jesus' birth is the timing of the census. The Bible states:
"In those days Caesar Augustus issued a decree that a census should be taken of the entire Roman world. This was the first census that took place while Quirinius was governor of Syria." (Luke 2:1-2, WEB)
The most definitive source on when Quirinius became governor of Syria is Josephus' Antiquities of the Jews. It records that Quirinius conducted a census as governor of Syria in 6 AD, after Herod's son Archelaus lost his throne and was exiled. Based on this, many people ask if Jesus was historically born in 6 AD, but this can actually be refuted by Luke's own account.
Luke records when John the Baptist began his ministry:
"In the fifteenth year of the reign of Tiberius Caesar-when Pontius Pilate was governor of Judea, Herod tetrarch of Galilee, his brother Philip tetrarch of Iturea and Traconitis, and Lysanias tetrarch of Abilene-during the high-priesthood of Annas and Caiaphas, the word of God came to John son of Zechariah in the wilderness." (Luke 3:1-2, WEB)
Emperor Tiberius reigned from 14-37 AD, so his 15th year would be 28 AD. John the Baptist began his ministry then, and after that comes the story of Jesus' baptism, which ends with:
"Now Jesus himself was about thirty years old when he began his ministry. He was, as was supposed, the son of Joseph, the son of Heli." (Luke 3:23, WEB)
We don't know exactly how long John ministered before baptizing Jesus, but this shows Jesus was not born in 6 AD. If he was born in 6 AD, he would have been baptized around 36 AD. 36 AD was the last year Pontius Pilate governed Judea. This would mean Jesus' public ministry started and stopped immediately, but the Bible records Jesus observing at least three Passovers. So Luke himself is already proving this census does not refer to 6 AD.
So when was this census conducted? Quirinius was a military commander in the BC era and defeated the Homonadenses in what is now southern Turkey. Afterwards, Cilicia was annexed to Syria, and scholars believe Quirinius stayed in the region as a special envoy and ordered a census along with the Syrian governors Saturninus (9-6 BC) or Varus (6-4 BC). That's why Luke says "This was the first census that took place while Quirinius was governor of Syria" (Luke 2:2), indicating it was Quirinius' first census.
But thinking this way creates another problem. If Jesus was baptized and began his ministry in 28-29 AD, it means he would have been born in 3-2 BC. This would mean he was born after Herod's death, creating a contradiction between Bible accounts. However, this problem can be solved rather simply. It can be resolved through the phrase "about thirty years old," which does not mean exactly thirty. The length of Jesus' public ministry is also estimated to be three and a half years based on the Passovers observed, but the Bible doesn't explicitly state it was exactly three and a half years. Some scholars even say there were five or more Passovers.
Additionally, December 25th, which people consider Christmas, doesn't mean Jesus was born on that exact day. In Roman times, various opinions emerged about Jesus' birth date. The first person to claim December 25th was the Roman historian Hippolytus. He thought Mary received the annunciation on March 25th (the spring equinox) and said Jesus was born on December 25th (the winter solstice), but this wasn't widely accepted at the time. It became established when Emperor Constantine officially designated December 25th as a holiday in 373 AD.
Separately, Jesus' birth can be estimated from John's Gospel's content related to temple construction, though there are some minor contradictions between records here too. But there are ways to resolve this issue as well. I'll explain this when we get to that part of the text.
Some of you may be confused by the various things I've said today. You might even develop an unconscious distrust of Christianity because things you firmly believed to be true might not be. But I want to tell you to cast away such distrust.
Even if we take these things for granted, they have nothing to do with the Bible. When Jesus was born doesn't affect the Bible's content at all. Just because something external to the Bible is wrong doesn't mean Christianity or the Bible is wrong. It's just that something someone started using long ago has been used for so long that we're now forced to keep using it due to social cost issues. That's all there is to it. I hope you won't attach more meaning than necessary to unimportant issues.
Recalling that clear and beautiful night 2000 years ago, I wish for the Lord's peace to be upon your day that God delights in. Whenever you read this story, I want to say this: Merry Christmas. Be happy in the Lord today.
"Glory to God in the highest heaven, and on earth peace to those on whom his favor rests." (Luke 2:14, WEB)
