Verses 76-79 comprise a prophecy devoted without qualification to John and his work.
From the very beginning, John and Jesus are allied in the salvation scheme. However, the Bible shows in interesting ways how John is subordinate to Jesus. For instance, in Luke 1:36, Mary and Elizabeth are shown to be related, probably cousins. Both women conceive in a miraculous way, but Mary's conception of Jesus by the Holy Spirit is far more miraculous. Then, when Elizabeth greets Mary (Luke 1:39-41), John, while still in her womb, leaps for joy in the presence of our Lord in His mother's womb. Finally, Luke 1:76 shows John to be only a prophet, but verses 32-35 show Jesus to be the Son of God and Heir to the throne of David.
John W. Ritenbaugh
Elijah and John the Baptist
John the Baptist's message laid the groundwork for the ministry of Jesus Christ who would reveal the knowledge of salvation and demonstrate that it comes about through the remission of sins.
Earl L. Henn (1934-1997)
Basic Doctrines: Salvation