He will go before him in the spirit and power of Elijah, 'to turn the hearts of the fathers to the children,' and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord."
That he may bring back the hearts of the fathers Here the angel points out the chief resemblance between John and Elijah. He declares that he was sent to collect the scattered people into the unity of faith: for to bring back the hearts of the fathers is to restore them from discord to reconciliation; from which it follows, that there had been some division which rent and tore asunder the people. We know how dreadful was the revolt of the people in the time of Elijah, how basely they had degenerated from the fathers, so as hardly to deserve to be reckoned the children of Abraham. Those who were thus disunited Elijah brought into holy harmony. Such was the reunion of parents with children, which was begun by John, and at length finished by Christ. Accordingly, when Malachi speaks of “turning the hearts of the fathers to the children,” (Malachi 4:5,) he intimates that the Church would be in a state of confusion when another Elijah should appear; and what was that state is plain enough from history, and will more fully appear in the proper place. The doctrine of Scripture had degenerated through countless inventions, the worship of God was corrupted by very gross superstition, religion was divided into various sects, priests were openly wicked and Epicureans, the people indulged in every kind of wickedness; in short, nothing remained sound. The expression, bring back the hearts of the fathers to the children, is not literally true; for it was rather the children who had broken the covenant and departed from the right faith of their fathers, that needed to be brought back But though the Evangelist does not so literally express that order of bringing back, the meaning is abundantly obvious, that, by the instrumentality of John, God would again unite in holy harmony those who had previously been disunited. Both clauses occur in the prophet Malachi, who meant nothing more than to express a mutual agreement. 