John the Baptizer is not to be confused with John the Apostle whose writings are in the New Testament.
John the Baptizer was a descendant of Levi and Aaron. John was the son of Zacharias the priest.
Like Abraham and Sarah, Zacharias and Elizabeth were elderly and childless when an angel of the Lord promised that John would be born to them. (Luke 1:5-25,41,57-80).
John was not the Christ [Messiah]
John the Baptizer confessed that he was not the Messiah (John 1:20).
John asked Jesus whether Jesus was the Christ: "Are you the One who is to come?"(Luke 7:20).
John was not the Prophet
John also denied that he was the prophet —the one in God’s promise to Moses: "From among their brethren I will raise up for them a prophet like you."(Deuteronomy 18:18,John 1:21).
John was not Elijah
John the Baptizer was not Elijah reincarnated or resurrected (John 1:19-23,note verse 21).
Although John was not Elijah in person, John did fulfil the promise concerning the "Elijah" who was to come (Malachi 4:5,Matthew 11:12-15,Matthew 17:9-13,Luke 1:17).
John the baptizer was Elijah’s antitype who came in the same spirit and power (Luke 1:17).
John was the "voice crying in the wilderness, 'Prepare the way for the Lord...'"(Luke 3:4,Isaiah 40:3).
Like Samson, John was under a lifetime vow of abstinence from all strong drink (Luke 1:15,Judges 13:3-7). Note also his food and clothing (Matthew 3:4,2Kings 1:8)
John bore testimony to Jesus as the Christ (John 1:6-9,15-37).
John the Baptizer was a revivalist who had the courage to "tell it like it is" (Matthew 3:1-12).
John's fiery preaching turned many sinners to righteousness and made "a people prepared for the Lord" (Luke 1:16-17).
John preached and practised "a baptism of repentance for the forgiveness of sins"(Mark 1:4)
John's baptism is like Christ's baptism. However, those baptized by John had later to also be baptized into Christ to receive the Holy Spirit (Acts 2:38,Acts 19:1-7).
John was called upon to baptize God's Son (Matthew 3:13-17).
John was beheaded by Herod Antipas (Herod the tetrarch) because of a foolish carte blanche oath Herod swore to his wife's dancing daughter (Matthew 14:1-13,Mark 6:14-29).
Note: The Irish playwright Oscar Wilde wrote a play in 1891 about this story. He named the girl, and the play, "Salome". The name "Salome" is not given to Herod's stepdaughter in the Bible, but in Josephus's Jewish Antiquities (Book XVIII,Chapter 5, 4).