Zacharias was a priest named of the division of Abijah in the days of Herod the king of Judea. His wife was of the daughters of Aaron and her name was Elizabeth. They were both righteous before God walking in all the commandments and ordinances of the Lord blameless yet they had no child because Elizabeth was barren and they were both well advanced in years. The angel said to Zacharias that his son would be great in the sight of the Lord and would drink neither wine nor strong drink. He would be filled with the Holy Spirit even from his mother's womb and would turn many of the children of Israel to the Lord their God. He would also go before Him in the spirit and power of Elijah to turn the hearts of the fathers to the children and the disobedient to the wisdom of the just to make ready a people prepared for the Lord. Luke 1:5-25 covers the announcement of John's birth to his father Zacharias. Verses 68-79 record Zacharias' hymn of praise to God for John. Verses 76-79 comprise a prophecy devoted without qualification to John and his work. The prophecy given to his father Zacharias had undoubtedly been communicated to him. The angel tells Zacharias before John's birth that he will go before Him in the spirit and power of Elijah to turn the hearts of the fathers to the children and the disobedient to the wisdom of the just to make ready a people prepared for the Lord.

Zechariah was a priest and the father of John the Baptist. As a result John was a Levite of the family of Aaron who would normally have served either in a synagogue or at the temple. Instead John preached in the countryside. This departure from expected priestly conduct prompted the Sanhedrin, controlled by the Pharisees, to send priests and Levites to question him about his identity and authority. The inquiry formed part of the larger presentation of belief in Christ by showing early religious opposition to the forerunner whose unusual ministry prepared the way for the Messiah whose identity the authorities would later place on trial.

Zacharias enters the discussion primarily through the debate over calculating the date of Christ's birth, a debate that some Christian apologists use to justify celebrating Christmas on December 25. As a priest, Zacharias belonged to the course of Abijah, the eighth of the twenty-four priestly courses described in I Chronicles 24. Since there were twenty-four courses and the Hebrew calendar normally contained fifty-one weeks, each course had to serve at least twice yearly, with three additional weeks required for service during the holy days of Unleavened Bread, Pentecost, and Tabernacles. The ancient scholar John Chrysostom attempted to calculate Zacharias' second course of Temple service, concluding it fell on the Day of Atonement, which he used to place John the Baptist's conception shortly afterward and, by extension, Jesus' conception six months later on March 25—yielding a December 25 birth date when nine months are added. However, Chrysostom's calculation is shown to be flawed because he was not a Sabbath keeper and did not account for the three extra weeks required for holy day service. Correcting for this error places Zacharias' second course in the thirty-fifth week of the year, near the end of October, which would push Jesus' conception to the end of April rather than March—undermining the December 25 calculation entirely. A more accurate reconstruction, based on scriptural evidence rather than Chrysostom's miscalculation, places Zacharias' first course of service (the eighth course) in the ninth week of the year, just before Pentecost, since the Days of Unleavened Bread would have shifted the timing. Because priests were required to remain in Jerusalem through Pentecost, Zacharias would have served during that festival week as well, raising the possibility—offered speculatively—that the angel's announcement to him regarding John's conception occurred on the day of Pentecost itself. Following this, Zacharias would have returned home, and John's conception would have taken place in mid- to late June. Calculating forward from this point places Jesus' conception in December, meaning His birth would have occurred during the fall holy day season rather than in winter. This detailed examination of Zacharias' priestly service serves a larger purpose: exposing how apologists for Christmas selectively manipulate biblical chronology to arrive at December 25, a date that conveniently coincides with the pagan festival of Saturnalia. The flawed use of Zacharias' service record exemplifies the broader pattern of historical and scriptural fudging employed to defend a tradition rooted in pagan custom rather than biblical instruction, reinforcing the broader argument that Christmas cannot be traced back to a genuine, divinely sanctioned observance of Christ's birth.