On December 25, many Christians observe Christmas to honor the birth of Jesus Christ, following the Gregorian calendar. However, the exact date of His birth remains uncertain and some academics think it was around the start of spring, which would put it near Easter, the holiday commemorating His resurrection. The first Christians did not observe the celebration of His birth.
Since the observance most likely started in the second century, the origin of this event and its December date can be traced back to the Greco-Roman world.There are at least three possible reasons for the December date. According to Sextus Julius Africanus, a Roman Christian historian, Jesus was conceived on March 25th, the same day he thought the universe was founded. He was born on December 25th after nine months in His mother’s womb.
In the third century, the Roman Empire, which had not yet adopted Christianity, celebrated the rebirth of the Unconquered Sun (Sol Invictus) on December 25th. This holiday symbolized the arrival of longer days after the winter solstice and was celebrated in conjunction with the well-known Roman festival of Saturnalia (a time when people gathered for feasts and exchanged gifts). The Indo-European deity Mithras, the god of light and faithfulness, was born on this date as well. At the time, Roman soldiers were becoming more and more devoted to his cult.
Christmas was first observed by the Church in Rome on December 25, AD, under Emperor Constantine’s rule. Some have hypothesized that the date was chosen for political reasons, namely to undermine the long-standing pagan celebrations, because Constantine had established Christianity as the official religion of the empire. However, this date was not commonly accepted in the Eastern Empire, where January 6th was chosen for another fifty years. Christmas didn’t become a significant Christian holiday until the ninth century.