Some misunderstand this verse because of a translation error in the King James and other versions of the Bible. In many Bibles, certain words are italicized if they have been added to the text by the translators to facilitate understanding. Notice that in Revelation 20:10 the word "are" in the phrase "where the beast and the false prophet are" is in italics. This present-tense verb is not in the original Greek text of Revelation; its tense is to be understood from the context.
According to the chronology of Revelation itself, both the Beast and the False Prophet will be cast alive into the Lake of Fire at the beginning of God's thousand-year reign on the earth (Revelation 19:20). By merely using God's explanation of what happens to human bodies when they are cast into fire, we find that they will be burned up (Psalm 37:20). Therefore, the phrase in Revelation 20:10 should be translated "where the beast and the false prophet were [or were cast]."
In Matthew 25:41, Jesus says, "Then He will also say to those on the left hand, 'Depart from Me, you cursed, into the everlasting fire prepared for the devil and his angels." Jesus plainly shows that the everlasting fire was prepared for Satan and his angels. However, He goes on to say that human beings who are ultimately judged unfit for eternal life are also to be cast into this very Lake of Fire. "And these will go away into everlasting punishment" (verse 46). He means that their punishment is eternal, that is, irrevocable.
When these people are cast into the Lake of Fire, then, it is by God's definition "the second death," from which there is no resurrection. "Then Death and Hades were cast into the lake of fire. This is the second death. And anyone not found written in the Book of Life was cast into the lake of fire" (Revelation 20:14-15). Notice also Revelation 21:8, "But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death."
Thus, human beings like the Beast and False Prophet will totally burn up and die in the Lake of Fire, while Satan and his demons will suffer eternal torment as described in the last part of Revelation 20:10: "And they [Satan and his demons] will be tormented day and night forever and ever."