That's just a lie you've been told. The Matthew 24 version of Christ's coming to gather His saints parallels 1 Thess.4 about the "asleep" saints Jesus brings with Him from heaven. The Mark 13 version is about the alive saints "caught up" to Jesus on that day. So both are parallels to what Paul taught in 1 Thess.4, which points to the LAST DAY because it mentions the resurrection there. THUS THE GATHERING OF THE SAINT IN CHRIST'S OLIVET DISCOURSE IS ABOUT HIS GATHERING OF HIS CHURCH.
Like I showed, the Rev.19:1-9 verses TIMING is AFTER... the tribulation. It is Millennium timing, when The LORD GOD Omnipotent REIGNETH, like it says there.
Jesus is not yet reigning over the nations DURING THE TRIBULATION TIMING. His reign with the Psalms 2 "rod of iron" begins at His coming. He gathers His Church on that same day of the 1st day of His future reign, thus ENDING the tribulation, and this present world, on the "day of the Lord".
The marriage supper is shown happening AFTER THE TRIBULATION, during Christ's reign.
Rev 19:2-3
2 For true and righteous are His judgments: for He hath judged the great whore, which did corrupt the earth with her fornication, and hath avenged the blood of His servants at her hand.
3 And again they said, "Alleluia. And her smoke rose up for ever and ever.
KJV
Rev 19:6-7
6 And I heard as it were the voice of a great multitude, and as the voice of many waters, and as the voice of mighty thunderings, saying, "Alleluia: for the Lord God omnipotent reigneth."
7 Let us be glad and rejoice, and give honour to Him: for the marriage of the Lamb is come, and His wife hath made herself ready.
KJV
"The marriage supper is shown happening AFTER THE TRIBULATION, during Christ's reign."
No way.
Here is the order from heaven to earth to Christ's reign...
Heaven...
19:1 And after these things I heard a great voice of much people in heaven, saying, Alleluia; Salvation, and glory, and honour, and power, unto the Lord our God:
2 For true and righteous are his judgments: for he hath judged the great whore, which did corrupt the earth with her fornication, and hath avenged the blood of his servants at her hand.
3 And again they said, Alleluia And her smoke rose up for ever and ever.
4 And the four and twenty elders and the four beasts fell down and worshipped God that sat on the throne, saying, Amen; Alleluia.
5 And a voice came out of the throne, saying, Praise our God, all ye his servants, and ye that fear him, both small and great.
6 And I heard as it were the voice of a great multitude, and as the voice of many waters, and as the voice of mighty thunderings, saying, Alleluia: for the Lord God omnipotent reigneth.
7 Let us be glad and rejoice, and give honour to him: for the marriage of the Lamb is come, and his wife hath made herself ready.
8 And to her was granted that she should be arrayed in fine linen, clean and white: for the fine linen is the righteousness of saints.
9 And he saith unto me, Write, Blessed are they which are called unto the marriage supper of the Lamb. And he saith unto me, These are the true sayings of God.
To earth....
19:11 And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war.
12 His eyes were as a flame of fire, and on his head were many crowns; and he had a name written, that no man knew, but he himself.
13 And he was clothed with a vesture dipped in blood: and his name is called The Word of God.
14 And the armies which were in heaven followed him upon white horses, clothed in fine linen, white and clean.
15 And out of his mouth goeth a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness and wrath of Almighty God.
16 And he hath on his vesture and on his thigh a name written, King Of Kings, And Lord Of Lords.
17 And I saw an angel standing in the sun; and he cried with a loud voice, saying to all the fowls that fly in the midst of heaven, Come and gather yourselves together unto the supper of the great God;
18 That ye may eat the flesh of kings, and the flesh of captains, and the flesh of mighty men, and the flesh of horses, and of them that sit on them, and the flesh of all men, both free and bond, both small and great.
19 And I saw the beast, and the kings of the earth, and their armies, gathered together to make war against him that sat on the horse, and against his army.
Christ's reign...
20:4 And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
5 But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
6 Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
All 3 are in sequential order in your Bible.
You sir, are reading it backwards.