5 “See, I will send the prophet Elijah to you before that great and dreadful day of the Lord comes. 6 He will turn the hearts of the parents to their children, and the hearts of the children to their parents; or else I will come and strike the land with total destruction.”
The last two verses of the last chapter of the last book of the Old Testament, Malachi are our verses of the day. However, let us look at the preceding verses in this last chapter for context.
1 “Surely the day is coming; it will burn like a furnace. All the arrogant and every evildoer will be stubble, and the day that is coming will set them on fire,” says the Lord Almighty. “Not a root or a branch will be left to them. 2 But for you who revere my name, the sun of righteousness will rise with healing in its rays. And you will go out and frolic like well-fed calves. 3 Then you will trample on the wicked; they will be ashes under the soles of your feet on the day when I act,” says the Lord Almighty.
4 “Remember the law of my servant Moses, the decrees and laws I gave him at Horeb for all Israel.
The Bible Project for Malachi video describes this chapter (all six verses) appropriately as the conclusion of not only of Malachi, but of the history of Israel. This is introduced in the final verses of chapter three about the final remnant:
16 Then those who feared the Lord talked with each other, and the Lord listened and heard. A scroll of remembrance was written in his presence concerning those who feared the Lord and honored his name.
17 “On the day when I act,” says the Lord Almighty, “they will be my treasured possession. I will spare them, just as a father has compassion and spares his son who serves him. 18 And you will again see the distinction between the righteous and the wicked, between those who serve God and those who do not.
The final end evildoers will be one of fire as stated in verses one and three above. However, for the faithful remnant the sun of righteousness will rise with healing in its rays. And you will go out and frolic like well-fed calves. We read in verse five Elijah will come and indeed he did come in the person of John the Baptist fulfilling the prophecy of verse six
And he will go on before the Lord, in the spirit and power of Elijah, to turn the hearts of the parents to their children and the disobedient to the wisdom of the righteous–to make ready a people prepared for the Lord.”
John the Baptist denied he was the literal Elijah, but Jesus made clear John was Elijah in spirit
And if you are willing to accept it, he is the Elijah who was to come.
What happened though was the dreadful day of the Lord [did] come and Jesus was rejected and crucified. Then in 70 AD the land was met with total destruction. The temple was torn down and Israel destroyed. But how bad was while Jesus was till among them? Jesus tells us how bad it got and how bad it remains for Jews who choose to follow Him.
21 “Brother will betray brother to death, and a father his child; children will rebel against their parents and have them put to death. 22 You will be hated by everyone because of me, but the one who stands firm to the end will be saved.
Will we be part to the faith remnant or the stubble?