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 will turn
The hearts of the fathers to the children,
And the hearts of the children to their fathers,
Lest I come and strike the earth with a curse.”

Jesus said that John the Baptist was Elijah who was to come. The Spirit of Elijah is the Spirit of repentance. The Spirit of repentance leads unto changing and turning unto the LORD. Repentance in itself, does not include entering in, only the calling of the LORD. Therfore, it is through the rejection and denial of entering in, both regarding the Person of Christ, and His spoken word, that leads unto falling away and inheriting the wrath of God, and His great and dreadful day. In the OT, the people inherited the Promised Land, after many first fell away, and then through straying from the continual spoken word of Christ, even those who entered in missed the first coming of the Person of Christ. And the same has happened regarding the falling away of the church, as people received Jesus, but then strayed from His continual spoken word, and thus will not be ready at His Second Coming. Before Israel entered into the Promised Land, those who fell away had despised the Promised Land, as Esau despised his birthright, and was the unprofitable servant. This is like the forerunner unto not being ready at Christ's Comings, whether His first, in the past, or His Second; because God is a giver, and there is no other way to know Him. Those who fell away through despising the Promised Land, and thus coming unto rejecting God, did not know God in love, as He is a giver, though they did desire things in lukewarmness and leanness; however, that is not the Person of God, but is the testimony of Ishmael, and leads unto the sons of Greece. Through understanding what repentance is, there is further understanding about what discipline is, as they both do not include the gaining of initiative (even gaining the initiative, to 'submit'), but the giving of wholeness, equity, love, peace, truth, knowledge, and comfort. The wrong types of repentance and discipline involve the gaining of initiative, and the administration of provocation, along with the falsehood of submitting through the attempted implementations of 'letting go and letting God' and worshiping Him wanting nothing. It is provocation namely, that is the very thing that is against what Malachi 4 speaks about regarding the fathers and children being turned unto each other. When those types of wrong repentance and discipline are used, it is nearly as if no matter what the 'receiver' does, in relation to discipline, if they do not accept it, they seem wrong in the eyes of the 'giver.' This gives place for usurping, and position into the Antichrist kingdom and kingdom of darkness.

In Deuteronomy 28, there is an outline of blessings and curses. Just because we do not follow the Law anymore does not mean that we are not to diligently obey the voice of the LORD, as spoken of in this chapter. Just as not following the Law anymore does not mean that we don't still gain from the OT. And the Promise in Jeremiah and Hebrews regarding the new birth, is one in which we now even have the Holy Spirit, and new insides, to be able to continually follow the voice of the LORD. And along with this, just as the Promise speaks, as we have the Law written on our hearts and minds, and are born again incorruptible, then we can not break the Law. Just as according to who our new persons are, we have never sinned, will never sin, do not sin, and can not sin; though the body of flesh still has corruption and sins. In these things, we can know that we also have the written word, written upon our hearts and minds, and that we can not stray from it; but still are to follow the spoken word of God, and continually. It is the boldness in coming to the throne of grace, that knows that we can hope, and expect to abide in the perfection of the new birth, through Promise, though also our outsides do have sin. When God speaks about 'the curse' as opposed to just saying 'a curse,' He is speaking about the curses that are in Deuteronomy 28 regarding not diligently obeying His voice. Diligently obeying His voice goes beyond finding right and wrong in actions and works; it actually means that God knows whether or not we are abiding in His oneness, and thus whether or not we are worshiping in Spirit and truth; and thus He knows if someone is only honoring Him with lipservice, or depending upon works, regardless of how holy and upright they may seem to be, even in relationship.

Isaiah 24:6
Therefore the curse has devoured the earth

The destruction that is spoken of in Isaiah 24-34, entails the curse of Deuteronomy 28, and is in effect, through the lack of entering in, along with the presence of the wickedness, of having the wrong types of repentance and discipline; thus Isaiah 24-34 have to do with the curse of Malachi 4:6. Therefore also, Isaiah 24-34 speaks about the Tribulation, and Isaiah 40-66 speaks about the Promises that overcome the Tribulation. And within these things, there are also the testimonies of those who fall away, who are called the LORD's but shall be divided, losing their talent, that is the vessel of honor, while they are destroyed (Isaiah 65:13-16 for example). This is true just as Jesus said that He will cast the unprofitable into outer darkness, and divide them in two, and slay them.

John the Baptist came before Jesus, and Jesus gave salvation:

Isaiah 61:2
To proclaim the acceptable year of the LORD,
And the day of vengeance of our God

Jesus read this when He began His ministry, also saying that it was fulfilled in Him. This verse shows the placement of how Elijah was to come, so that God wouldn't smite the earth with the curse, but the curse and His vengeance comes as people have the wrong types of repentance and discipline. One of the largest examples of false discipline and repentance is found in the religious leaders of Jesus' day, for example:

Matthew 23:27
“Woe to you, scribes and Pharisees, hypocrites! For you are like whitewashed tombs which indeed appear beautiful outwardly, but inside are full of dead men’s bones and all uncleanness."

This verse correlates to the old prophet who buried the prophet who was killed by the lion, in his own tomb, in 1 Kings 13. And God also brings back upon their own heads, the iniquity of the religious, just as in Revelation:

Revelation 18:6-7
Render to her just as she rendered to you, and repay her double according to her works; in the cup which she has mixed, mix double for her. 7 In the measure that she glorified herself and lived luxuriously, in the same measure give her torment and sorrow; for she says in her heart, ‘I sit as queen, and am no widow, and will not see sorrow.’

But God bringing iniquity back on the heads of the wicked, does not mean that we recompense, it means that we have the two swords of the LORD, that are mentioned by Jesus, in speaking to Peter; the two swords being the Holy Spirit, and the Spirit of Jesus Christ (Jesus in One with the Holy Spirit, but He also has His own Spirit), which are implemented in prayer and the outworkings of our faith, just as God says for us to give room for vengeance.

And along with these things, those whom the LORD saves, even receive the repentance of the harlot, (the religious, Babylon).

Isaiah 23:15-18
15 Now it shall come to pass in that day that Tyre will be forgotten seventy years, according to the days of one king. At the end of seventy years it will happen to Tyre as in the song of the harlot:
16 “ Take a harp, go about the city,
You forgotten harlot;
Make sweet melody, sing many songs,
That you may be remembered.”

17 And it shall be, at the end of seventy years, that the LORD will deal with Tyre. She will return to her hire, and commit fornication with all the kingdoms of the world on the face of the earth. 18 Her gain and her pay will be set apart for the LORD; it will not be treasured nor laid up, for her gain will be for those who dwell before the LORD, to eat sufficiently, and for fine clothing.