19 This is the testimony of John, when the Jews sent priests and Levites to him from Jerusalem to ask him, “Who are you?” 20 And he confessed and did not deny; and this is what he confessed: “I am not the Christ.” 21 And so they asked him, “What then? Are you Elijah?” And he *said, “I am not.” “Are you the Prophet?” And he answered, “No.” 22 Then they said to him, “Who are you? Tell us, so that we may give an answer to those who sent us. What do you say about yourself?” 23 He said, “I am the voice of one calling out in the wilderness, ‘Make the way of the Lord straight,’ as Isaiah the prophet said.”

John 1:19-23 (NASB)

Who is John?

The Jews (religious leaders in Jerusalem) wanted to know who John the Baptist was. He was gaining a lot of attention and disciples. Politically, there was risk of him causing a stir and bringing trouble from the Romans. Religiously, he acted and spoke like a prophet which they thought could be a sign of the coming Messiah. 

John is NOT…

John first made it clear who he was not:

• The Messiah – “John’s ministry consisted of pointing the Messiah out to others so that they would follow Him. Therefore it would have been counterproductive to allow anyone to confuse him with the Messiah.” (planobiblechapel.org)
• Elijah – Remember when we studied Malachi 4:5-6? The last message was about Elijah, the OT prophet. Malachi had predicted that Elijah would return to warn of the coming “great and dreadful day of the Lord”. Was John Elijah? No.
• The Prophet – The Lord had predicted through Moses in Deut. 18:15-18 that The Prophet would come. Was John this prophet? No. “The Jews incorrectly failed to identify this Prophet with Messiah (cf. v. 25; 6:14; 7:40-41).” (planobiblechapel.org)

John IS…

So who is he? The Jews wanted to know. “We know who you are not, but who are you?”, they asked. John leveled with them by quoting from Isaiah 40:3. Isaiah had predicted John’s coming hundreds of years before and the Jews knew this. Since Malachi, they had received no other word from God so they waited. Now he is here. John came to prepare the way, to point people to the Messiah. We do the same!

Those who sought the Lord must have thought this was really cool – to see the fulfillment of prophecy before their very eyes. As a result, as noted above, John was developing attention and a following. There were still faithful Jewish people who were holding onto the promises of God, looking for Messiah.