According to Luke: An Analytical Commentary

Luke 1:16-17

16 And many of the children (descendants) of Israel (Jacob; cf. Genesis 32:28) shall he turn (convert, bring back) to the Lord their God (true repentance and restoration to covenant faithfulness).

17 And he shall go before him (John as forerunner of the Christ; cf. Malachi 3:1)

in the spirit and power of Elias (Elijah’s prophetic spirit and boldness; cf. Malachi 4:5-6 and Matthew 17:12-13),

to turn the hearts of the fathers to the children (see lesson #3 at end the of chapter 1), and the disobedient (Not mere external disobedience but inward obstinacy, rejection of God’s authority or revealed will.) to the wisdom of the just (righteous mindset and living), to make ready (prepare spiritually and morally) a people prepared (the passive voice implies divine agency: it is ultimately God who prepares them, using John as His instrument) for the Lord (readied for the Messiah’s arrival; cf. Isaiah 40:3).