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 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.
According to the Jewish historian Josephus (who wrote after 70 Ad), John the Baptist was a Jewish preacher in the time of Pontius Pilate (Ad 26-36). He called the people to repentance and to a renewal of their covenant relation with God. He was imprisoned and eventually put to death by Herod Antipas (son of Herod the Great, who was king when Jesus was born) for denouncing Herod's marriage to Herodias, the wife of his still-living brother Philip. In order to marry Herodias, Herod divorced his first wife, the daughter of King Aretas of Damascus, who subsequently made war on Herod, a war which, Josephus tells us, was regarded by devout Jews as a punishment for Herod's murder of the prophet John.
In the Book of Acts, we find sermons about Jesus which mention His Baptism by John as the beginning of His public ministry (see Acts 10:37; 11:16; 13:24). We also find accounts (see Acts 18:24; 19:3) of devout men in Greece who had received the baptism of John, and who gladly received the full message of the Gospel of Christ when it was told them.
Luke begins his Gospel by describing an aged, devout, childless couple, the priest Zechariah and his wife Elizabeth. As Zechariah is serving in the Temple, he sees the angel Gabriel, who tells him that he and his wife will have a son who will be a great prophet, and will go before the Lord "like Elijah." (The Jewish tradition had been that Elijah would herald the coming of the Messiah = Christ = Annointed = Chosen of God.) Zechariah went home, and his wife conceived. About six months later, Gabriel appeared to the Virgin Mary, a kinswoman of Elizabeth, and told her that she was about to bear a son who would be called Son of the Most High, a king whose kingdom would never end. Thus Elizabeth gave birth to John, and Mary gave birth six months later to Jesus.
After describing the birth of John, Luke says that he grew, and "was in the wilderness until the day of his showing to Israel." The people of the Qumran settlement, which produced the Dead Sea Scrolls, sometime use the term "living in the wilderness" to refer to residing in their community at Qumran near the Dead Sea. Accordingly, it has been suggested that John spent some of his early years being educated at Qumran.
All of the gospels tell us that John preached and baptized beside the Jordan river, in the wilderness of Judea. He called on his hearers to repent of their sins, be baptized, amend their lives, and prepare for the coming of the Kingship of God. He spoke of one greater than himself who was to come after. Jesus came to be baptized, and John told some of his disciples, "This is the man I spoke of." After His baptism by John, Jesus began to preach, and attracted many followers. In fact, many who had been followers of John left him to follow Jesus. Some of John's followers resented this, but he told them: "This is as it should be. My mission is to proclaim the Christ. The groomsman, the bridegroom's friend, who makes the wedding arrangements for the bridegroom, is not jealous of the bridegroom. No more am I of Jesus. He must increase, and I must decrease." (John 3:22-30)
John continued to preach, reproving sin and calling on everyone to repent. King Herod Antipas had divorced his wife and taken Herodias, the wife of his (still living) brother Philip. John rebuked him for this, and Herod, under pressure from Herodias, had John arrested, and eventually beheaded. He is remembered on some calendars on the supposed anniversary of his beheading, 29 August.
When John had been in prison for a while, he sent some of his followers to Jesus to ask, "Are you he that is to come, or is there another?" (Matthew 11:2-14) One way of understanding the question is as follows: "It was revealed to me that you are Israel's promised deliverer, and when I heard this, I rejoiced. I expected you to drive out Herod and the Romans, and rebuild the kindom of David. But here I sit in prison, and there is no deliverance in sight? Perhaps I am ahead of schedule, and you are going to throw out the Romans next year. Perhaps I have misunderstood, and you have a different mission, and the Romans bit will be done by someone else. Please let me know what is happening."
Jesus replied by telling the messengers, "Go back to John, and tell him what you have seen, the miracles of healing and other miracles, and say, 'Blessed is he who does not lose faith in me.'"
He then told the crowds: "John is a prophet and more than a prophet. He is the one spoken of in Malachi 3:1, the messenger who comes to prepare the way of the Lord. No man born of woman is greater than John, but the least in the Kingdom of God is greater than John."
This has commonly been understood to mean that John represents the climax of the long tradition of Jewish prophets looking forward to the promised deliverance, but that the deliverance itself is a greater thing. John is the climax of the Law. He lives in the wilderness, a life with no frills where food and clothing are concerned. He has renounced the joys of family life, and dedicated himself completely to him mission of preaching, of calling people to an observance of the law, to ordinary standards of virtue. In terms of natural goodness, no one is better than John. But he represents Law, not Grace. Among men born of woman, among the once-born, he has no superior. But anyone who has been born anew in the kingdom of God has something better than what John symbolizes. (Note that to say that John symbolizes something short of the Kingdom is not to say that John is himself excluded from the Kingdom.)
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 Hamisphere, these dates embody a rich symbolism. (Note: Listmembers living in Australia, New Zealand, South Africa, southern South America, or elsewhere in the Southern Hemisphere, press your delete keys Now!) 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."
(Of course, it is to be noted that none of this symbolism proves anything, since the Scriptures do not tell us that Jesus was born on 25 December. The symbolism of the dates is used by Christians, not as evidence, but as material for the devout imagination.)
Almighty God, by whose providence thy servant John the Baptist Was wonderfully born, and sent to prepare the way of thy Son our Savior by preaching repentance: Make us so to follow his doctrine and holy life, that we may truly repent according to his preaching; and after his example constantly speak the truth, boldly rebuke vice, and patiently suffer for the truth's sake; through the same thy Son Jesus Christ our Lord, who liveth and reigneth with thee and the Holy Spirit, one God, for ever and ever.
Almighty God, by whose providence your servant John the Baptist Was wonderfully born, and sent to prepare the way of your Son our Savior by preaching repentance: Make us so to follow his teaching and holy life, that we may truly repent according to his preaching; and, following his example, constantly speak the truth, boldly rebuke vice, and patiently suffer for the truth's sake; through Jesus Christ your Son our Lord, who lives and reigns with you and the Holy Spirit, one God, for ever and ever.
First Lesson: Isaiah 40:1-11 (Isaiah speaks of someone who will cry out, "Prepare the way of the Lord.")
Psalm 85 (The long exile is over, God has retored his people, mercy and truth are reconciled.)
Second Lesson: Acts 13:14b-26 (Paul preaches about Christ, and how the prophets, including John the Baptist, all pointed forward to him.)
The Holy Gospel: Luke 1:57-80 (The birth of John the Baptist; his father Zechariah's song of praise.)
Psalm 85 or 85:7-13
Luke 1:57-80 (Adv)