How and why was the birth of John unique?

Answer 1

A:Luke's Gospel is now known to have been based largely on Mark's Gospel and the hypothetical 'Q' document, but the story of the birth of John the Baptist is unique to this gospel, so we do not know where its author learnt of the birth. The story in some ways reflects the story of the birth of Isaac. Zacharias laughed just as Abraham did, when told that his elderly wife would bear a child. This story differs from the Old Testament account because Zacharias was punished for his disbelief by being struck dumb until the birth of John.

Although we know that John the Baptist was a historical person, it is possible that the account of his birth is not historically true. Uta Ranke-Heinemann (Putting Away Childish Things) believes that Zechariah and Elizabeth were literary creations and that the Lucan story is fictional.

Another Answer:

Assuming your are asking about the Baptist, the Bible notes only 3 men whom God 'knew' before He formed them in the womb: Jeremiah, John the Baptist, and Jesus.