Isn't the Great White Throne judgement in
Revelation 20 after the Millennium?
That is correct, but, that is not the Sheep and Goat Judgment described in Matthew 25, which follows the events of the Tribulation in Matthew 24.
How does that push the Rapture to before the Tribulation?
It doesn't, the Great White Throne judgment is separated from the end of the Tribulation by one thousand years, seventy five days:
Daniel 12:7-12
King James Version (KJV)
7 And I heard the man clothed in linen, which was upon the waters of the river, when he held up his right hand and his left hand unto heaven, and sware by him that liveth for ever that it shall be for a time, times, and an half; and when he shall have accomplished to scatter the power of the holy people, all these things shall be finished.
8 And I heard, but I understood not: then said I, O my Lord, what shall be the end of these things?
9 And he said, Go thy way, Daniel: for the words are closed up and sealed till the time of the end.
10 Many shall be purified, and made white, and tried; but the wicked shall do wickedly: and none of the wicked shall understand; but the wise shall understand.
11 And from the time that the daily sacrifice shall be taken away, and the abomination that maketh desolate set up, there shall be a thousand two hundred and ninety days.
12 Blessed is he that waiteth, and cometh to the thousand three hundred and five and thirty days.
The first reference to time is 3 1/2 years according to the Jewish Calendar (1240 days). The second reference to time gives an additional 30 days; the last reference makes a total of 75 days after the 3 1/2 years.
That is with the time beginning at the time which most likely coincides with Daniel 9:27...
Daniel 9:27
King James Version (KJV)
27 And he shall confirm the covenant with many for one week: and in the midst of the week he shall cause the sacrifice and the oblation to cease, and for the overspreading of abominations he shall make it desolate, even until the consummation, and that determined shall be poured upon the desolate.
That event takes place in the middle of the Seven Year Period described in Revelation, which is further supported (a seven year Tribulation Period) by the fact that the Two Witnesses and the Antichrist both have forty two month ministry/rampage.
I see it as Satan being bound at the end of the Tribulation, then a 75 day establishment period in which the Sheep and judgment take place, then Satan is loosed and we see those who rebel against God and join with Satan destroyed. So if you are pre-millennial, you can distinguish between the two judgments.
We see in Matthew 24:27-28 reference to the "eagles" and carcasses. This is made clear here:
Luke 17:24
King James Version (KJV)
24 For as the lightning, that lighteneth out of the one part under heaven, shineth unto the other part under heaven; so shall also the Son of man be in his day.
Luke 17:34-37
King James Version (KJV)
34 I tell you, in that night there shall be two men in one bed; the one shall be taken, and the other shall be left.
35 Two women shall be grinding together; the one shall be taken, and the other left.
36 Two men shall be in the field; the one shall be taken, and the other left.
37 And they answered and said unto him, Where, Lord? And he said unto them, Wheresoever the body is, thither will the eagles be gathered together.
The answer to "Where are they taken" is...in judgment.
Unbelievers are put to death during this time, and believers remain alive. The only ones mentioned as being raised from the dead after the Tribulation are the Tribulation Martyrs who are clearly identified here:
Revelation 20:4-5
King James Version (KJV)
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.
They did not take mark of the beast, which is specific to the events described in Revelation. They did not worship him. They did not fail in their testimony of Christ and were thus executed.
Now, the first thing someone is going to think when they read of the First Resurrection is that this has a sequential meaning, but, protos is not always used for sequence, but speaks of rank. There are two types of resurrections spoken of in Scripture, the resurrection unto life, and the resurrection unto damnation. When the thousand years are up, those not raised at this time are raised to stand before the Great White Throne.
This is just a brief description in response to this question, there is much more that would need to be considered in order to give this the time it deserves. So hope that helps in regards to this question.
Continued...