How do we know that the prophecy of John's birth is true?

Gabriel's announcement to Zechariah about John’s conception serves as a direct revelation from God, demonstrating His sovereignty and faithfulness in fulfilling His promises. The birth of John was prophesied in both Malachi and Isaiah, confirming his role as the herald of Christ. When Jesus later affirms John's greatness in Matthew 11:11, it reinforces the legitimacy of the prophetic message given to Zechariah. Therefore, the alignment of events in the New Testament with the Old Testament prophecies provides strong evidence of the truth behind John the Baptist's identity and purpose.