Zechariah (John’s father) knew John was to be the long-awaited Elijah, so why would John deny it in this exchange with the priests and Temple assistants sent by the Jewish leaders?
When they asked Who are you?
John 1:20-21 [John] came right out and said, ‘I am not the Messiah.’
‘Well then, who are you?’ they asked. ‘Are you Elijah?’
‘No’, he replied.
‘Are you the Prophet we are expecting?’
‘No.’
This would have been confusing. They were all expecting one of the above. These assistants needed something to take back to those who sent them.
When asked what he did have to say for himself, John replied in the words of the prophet Isaiah:
John 1:23 I am a voice shouting in the wilderness,
‘Clear the way for the Lord’s coming!’
It’s controversial: did John lie, or was it more of an answer of the type If you have to ask, I’m not telling you? John never shied from his role of preparing the way for Jesus.
Jesus put it this way:
Matthew 11:14And if you are willing to accept what I say, he is Elijah, the one the prophets said would come.
The issue is more that the rulers didn’t recognise it, a point made by Jesus some time later:
Matthew 17:12 But I tell you, Elijah has already come, but he wasn’t recognized, and they chose to abuse him. And in the same way they will also make the Son of Man suffer.