Our principal sources of information about John the Baptist are

  1. references to his birth in the first chapter of Luke,
  2. references to his preaching and his martyrdom in the Gospels, with a few references in Acts, and
  3. references in the writings of the Jewish historian Josephus to his preaching and martyrdom, references which are consistent with the New Testament ones, but sufficiently different in the details to make direct borrowing unlikely.

Traditionally, the Birth of Jesus is celebrated on 25 December. That means that the Birth of John is celebrated six months earlier on 24 June. The appearance of Gabriel to Mary, being assumed to be nine months before the birth of Jesus, is celebrated on 25 March and called the Annunciation, and the appearance of Gabriel to Zechariah in the Temple is celebrated by the East Orthodox on 23 September. At least for Christians in the Northern Hemisphere, these dates embody a rich symbolism. John is the last voice of the Old Covenant, the close of the Age of Law. Jesus is the first voice of the New Covenant, the beginning of the Age of Grace. Accordingly, John is born to an elderly, barren woman, born when it is really too late for her to be having a child, while Jesus is born to a young virgin, born when it is really too early for her to be having a child. John is announced (and conceived) at the autumnal equinox, when the leaves are dying and falling from the trees. Jesus is announced (and conceived) at the vernal equinox, when the green buds are bursting forth on the trees and there are signs of new life everywhere. John is born when the days are longest, and from his birth on they grow steadily shorter. Jesus is born when the days are shortest, and from his birth on they grow steadily longer. John speaks truly when he says of Jesus, “He must increase, but I must decrease.”

(Adapted from James Kiefer)