In this verse, Jesus is addressing the crowd about John the Baptist, making a profound declaration about his role in God's plan. By referring to John as 'the Elijah who was to come,' Jesus connects John with the Old Testament prophecy found in Malachi 4:5, which speaks of Elijah's return before the 'great and dreadful day of the Lord.' This doesn't mean John is literally Elijah reincarnated, but rather that he embodies the spirit and mission of Elijah, preparing the way for Jesus, the Messiah.
This identification highlights the continuity between the Old and New Testaments, showing that God's promises are being fulfilled in unexpected ways. It also challenges the audience to be open to God's revelations, which might not align with their preconceived notions. Jesus' statement is an invitation to recognize the significance of John's ministry and its role in the larger narrative of salvation. It calls for a willingness to accept God's messengers and the transformative message they bring, urging a readiness to embrace the new covenant that Jesus inaugurates.