Malachi 4:5-6, “Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the LORD: (6) And he shall turn the heart of the fathers to the children, and the heart of the children to their fathers, lest I come and smite the earth with a curse.”
John the Baptist came in the spirit and power of Elijah. He was bold in preaching and uncompromising in the Word of God. This was fulfilled in the coming of John the Baptist.
Luke 1:17, “And he [John] shall go before him in the spirit and power of Elias, 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.”
Matthew 11:13-14, “For all the prophets and the law prophesied until John. (14) And if ye will receive it, this is Elias, which was for to come.”
John 1:21, “And they asked him, What then? Art thou Elias? And he saith, I am not. Art thou that prophet? And he answered, No.”