‘’19Now this was John’s testimony when the Jewish leaders in Jerusalem send priests and Levites to ask him who he was. 20 He did not fail to confess, but confessed freely, I am not the Messiah. 21 They asked him, then who are you? Are you Elijah? He said, I am not. Are you the prophet? He answered no.
Priests were Israelites from of the family lineage of Aaron, of the tribe of Levi, one of the 12 tribes of Israel. Levites were Israelites from the tribe of Levi.
John the Baptist testified that he was not the Messiah, not Elijah and not the prophet of Deut. 18:15. His public ministry ended 400 years of prophetic silence.
He was the last of the Old Testament prophets. An ascetic, living in the wilderness, cloth in camel hair, subsisting on locust and wild honey, he preached a message of repentance by water baptism in the spirit of Elijah.
22 Finally they said, who are you? Give us an answer to those who sent us. What do you say about yourself? 23John replied in the words of Isaiah the prophet, “I am the voice of the one calling in the wilderness, make straight the way of the Lord.’’
John the Baptist was the voice in the wilderness preparing the way for the coming Messiah, Isa 40:3, Matt 3:3, Mark 1:2-3, and Luke 3:3-6. He was the voice, not the Word, the messenger, not the Message, the way maker, not the Way.