He will turn many of the children of Israel to the Lord, their God.
The term "turn back" (Gr. epistrepho) became a technical term for Christian conversion (cf. Acts 9:35; 2 Corinthians 3:16; 1 Thessalonians 1:9; 1 Peter 2:25). Essentially it means turning from idols to the true God. Turning people to God was the responsibility of every true priest (Malachi 2:6). The meaning of the Malachi quotation is probably that when restoration comes there will be human reconciliation and love rather than estrangement and selfishness. [Note: Marshall, The Gospel . . ., p. 60.] People would clean up their interpersonal relationships in preparation for Messiah’s appearing.