In religious art, wherever John the Baptist and Jesus appear in the same painting, you can almost guarantee that John the Baptist will be portrayed with his index finger extended, pointing at Jesus. That's who John is. He's a witness, always pointing to Jesus. John is very clear about who he is and who he's not. "I am not the Messiah. ... I am not Elijah. ... I am the voice of one crying out in the wilderness, 'Make straight the way of the Lord'" (John 1:20-23).
John's job description as one who points to Jesus is also our job description as Christians. We are called to be witnesses to Christ, testifying to the world how God has come to us in the flesh to bring peace, reconciliation and hope. As Christians, we are always to be on the lookout for any sign or piece of evidence pointing to how God in Christ is present in the world. And whenever we see these signs and evidence, we point to them for all the world to see.
John 1:19-23 (NRSV)
19 This is the testimony given by John when the Jews sent priests and Levites from Jerusalem to ask him, "Who are you?"
20 He confessed and did not deny it, but confessed, "I am not the Messiah."
21 And they asked him, "What then? Are you Elijah?" He said, "I am not." "Are you the prophet?" He answered, "No."
22 Then they said to him, "Who are you? Let us have an answer for those who sent us. What do you say about yourself?"
23 He said, "I am the voice of one crying out in the wilderness, "Make straight the way of the Lord,' " as the prophet Isaiah said.