"But when the Son of Man comes in His glory, and all the angels with Him, then He will sit on His glorious throne, and all the nations will be gathered before Him . . ." (Matthew 25:31,32)
This judgment is not the judgment of the great white throne (Revelations 20:11-15). A careful comparison of the two judgments will establish the following facts:
01) The judgment of the nations will take place "when the Son of Man comes in His glory . . . then He will sit on His glorious throne." The great white throne is never called "the Throne of His Glory" (Revelation 20:11-15).
02) At this judgment, He will judge the nations (Joel 3:11-16). At the white throne judgment, He will judge the wicked dead.
03) At this judgment, there will be no resurrection of the dead. At the white throne all the wicked dead are raised: "The sea gave up the dead which were in it, and death and Hades gave up the dead which were in them . . ." (Revelation 20:13).
04) At this judgment, the judge is God "the King" judging the living nations in His earthly kingdom. At the great white throne, the judge is God, judging only the wicked dead.
05) At this judgment, there are no books opened. At the great white throne, the "books were opened."
06) At this judgment, there are three classes judged: "sheep - the saved (Revelation 7:9-17); "goats - the unsaved (2 Thessalonians 1:7-10); "tribes - the elect of Israel (Revelation 7:1-8 & Romans 11:25-28). At the great white throne, there is only one class: "the dead."
07) At this judgment, the King gives the kingdom to those who have eternal life. At the great white throne, there are no saved and no kingdom; they are all "thrown into the lake of fire." "
(From : Bible Foundation Course Lesson 06-04)