Allen,
If we read Rev 20:14-15 (NIV) it helps to give us a larger picture:
'14 Then death and Hades were thrown into the lake of fire. The lake of fire is the second death. 15 Anyone whose name was not found written in the book of life was thrown into the lake of fire'.
Verse 14 reinforces the view that the lake of fire is not something to be taken literally, but is symbolical. Death and Hades are here personified and provide the picture of being thrown into the lake of fire with the beast, false prophet and the devil (see v. 10).
So it is impossible to arrive at a literal understanding and John seems to be confirming that death and the grave will be completely destroyed.
In v. 14, the statement of 'the lake of fire is the second death' anticipates what is stated in v. 15. It does not seem in v. 14 that John, the Revelator, is talking about the death of Death (that wouldn't make sense), but he moves to the destruction of death and the judgment of the dead, based on what they had done (v. 13).
Those who have died are judged, not by works but by what was written in the book of life (v. 12, 15). Is his/her name in that book? If our names are not in that book, we are thrown into the symbolical lake of fire. However, the language, 'lake of fire', even though not literal, is surely conveying in stark symbol form what a horrible experience it will be after the final judgment for all enemies of God's righteousness through Christ.
Even though it is symbolical language, 'the lake of fire' sure conveys the horrible experience of everlasting punishment for all unbelievers after the final judgement. This is like the Jewish term, Gehenna, e.g. Matt 10:28 (ESV) .
Oz