What does John 1:23 mean?
John the Baptist makes a single clear claim to fulfill Old Testament prophecy. He is "the voice" of Isaiah 40:3, from the Greek word phone. Jesus, on the other hand, is "the Word," from the Greek word logos (John 1:1). The "voice" brings awareness of "the Word," which people are then expected to respond to. There, in the desert outside of Jerusalem, John the Baptist was crying out, making "the way" for the Lord (Malachi 3:1; Matthew 3:1–3).People hearing this prophecy would have understood it as "making a road," meaning a path for the incoming King. Our conversations, and our discussions, are meant to "make a way" for Christ to reach others (2 Corinthians 10:5; 1 Peter 3:15–16).
John the Baptist is also reassuring others by denying that he is the Messiah. What he preaches is not a new religion, nor even a new revelation. It is the fulfillment of what was already prophesied (Isaiah 9:2–7; Jeremiah 33:15–16). This is not God changing His mind—it is God completing His plan.