The Apostle John does not hesitate to identify John as a “man sent from God,” “a witness, to bear witness about the light” (John 1:6-8). John the Baptist always points away from himself toward the coming Christ, and he is fully aware of the nature of his calling.
The priests and Levites are not on a generic mission from Jerusalem. They want an answer to a very specific question, even if it seems vague: “Who are you?” John’s immediate reply, “I am not the Christ,” and their follow up “What then? Are you Elijah?” demonstrates that they, with the Pharisees, are wondering whether John is the promised Messiah. They know that Christ is coming, though they mistake the signs and wonder whether John might be the promised one. Only with John’s repeated denials do they finally ask him directly about his mission. That the Pharisees know that Christ is coming, however, only highlights their hardness of heart: “He came to his own, and his own people did not receive him” (John 1:11). They knew and expected Him, yet rejected Him when He appeared.
John denies being Elijah, the fulfillment of Malachi 4:5-6, which is intriguing, since Christ Himself makes this identification (Matthew 11:14). It may be that John, since he is rejecting the false notions of the Pharisees, speaks against their misunderstandings. The bystanders at the cross purposely distort Jesus’ words, saying “Behold, he is calling Elijah” (Matthew 27:47; Mark 15:35), which suggests that they are expecting Elijah in the flesh to come in a miraculous way. Jesus, however, connects John the Baptist to his office, and therefore gives us the correct understanding of Malachi’s prophecy.
John also denies being “the Prophet,” a reference to the prophecy of Moses in Deuteronomy 18:15-22. Moses says that the Lord “will raise up for you a prophet like me,” a qualification that no other Old Testament prophet met, since Moses knew the Lord “face to face” (Deuteronomy 34:10-12). Jesus says of John that “among those born of women none is greater” (Matthew 11:11; Luke 7:28), which implies that John is a greater prophet than Moses. However, John’s denial here suggests that “the Prophet” is a reference to Christ as the greatest of all the prophets. If John stands in the office of Elijah, then Christ is the greater Elisha, who worked more miracles than his predecessor and indeed bore a double portion of the Spirit (2 Kings 2:9).
After rejecting their false notions, John identifies himself as “the voice of one crying out in the wilderness,” a plain reference to Isaiah 40:3. There, the voice is told to cry out the good news: “Comfort, comfort my people, says your God. Speak tenderly to Jerusalem, and cry to her that her warfare is ended, that her iniquity is pardoned, that she has received from the Lord’s hand double for all her sins” (Isaiah 40:1-2). It is a preparation to the Lord’s declaration in the following chapters that He is the living God, the Help of Israel. He will not share his glory with empty idols, but He will act when He sends His servant, “my chosen, in whom my soul delights” (Isaiah 42:1). John’s call for repentance, therefore, includes this positive affirmation by extension: Turn away from your sins, your false notions, and your idols, and return to the living God, the Fear of Jacob, the Fortress of Israel! He will not share His glory with another, but He will act when He sends the one whose sandals I am not worthy to untie.
The messengers of the Pharisees again demonstrate the hardness of their hearts by showing that they understand the purpose of Baptism, at least dimly. If John is not the Christ, Elijah, or the Prophet, then why is he baptizing, since this practice belongs to them (John 1:25)? This is also shown by some of the Pharisees and Sadducees who tried to be baptized (Matthew 3:7; Luke 3:7). They recognize that this practice belongs to the coming of Christ, but they have come for the wrong reasons, not by faith, but as if it were based on works (Romans 9:30-33).
John answers them by pointing again to his office and rebuking them for their unbelief. His baptism, because it would give way to the Sacrament of Baptism (Acts 18:25; 19:1-7), was preparatory and temporary. It, like John, pointed ahead to the coming of Christ, and it ceased with John’s office when Christ appeared. However, John’s rebuke that “among you stands one you do not know” shows that the Pharisees, despite knowing the prophecies and knowing that Christ was near, stumbled over the rock of offense. They knew that Christ was near, and yet seeing, they did not see. “Yet among the mature we do impart wisdom, although it is not a wisdom of this age or of the rulers of this age, who are doomed to pass away. But we impart a secret and hidden wisdom of God, which God decreed before the ages for our glory. None of the rulers of this age understood this, for if they had, they would not have crucified the Lord of glory” (1 Corinthians 2:6-8).