The Great White Throne Judgment concludes with death and hell (hades, the grave) being cast into the lake of fire, which is defined for us in Revelation 20:14 as the second death. So, if death and the grave were cast into the lake of fire and destroyed, what would that look like?
Prior to the resurrection of the just and the unjust (Acts 24:15), men slept or were dead when they departed from the land of the living. In other words, a man’s “thoughts perish” (Psalm 146:4) when he died. He was no longer conscious of anything, whether in the “land of the living” or in the grave. After death, if his children honored his memory, he was unaware of any of it (Job 14:21), and, if he left an inheritance, it was impossible for him to see who received his goods (Psalm 39:6). Neither, was a man able to praise God or worship the Lord in the grave (Psalm 6:5; 30:9; Isaiah 38:18). Therefore, if death and hades (the grave) were cast into the lake of fire and destroyed, men couldn’t die from that point onwards. If a man died, his spirit would live on and be judged immediately by Christ, according to the manner of the judgment of the just and the unjust mentioned above. In other words, there is no death for man anymore, not since 70 AD, when Jesus came to judge the living and the dead. Death and the grave were destroyed in the coming of Christ.
John concludes by saying whosoever was not found written in the Book of Life was cast into the lake of fire (Revelation 20:15). This is the fate of all the wicked. So, what exactly would such a fate look like? First of all, since death and the grave (hades) are also cast into the lake of fire (Revelation 20:14), then death, as it was known prior to the Second Coming of Christ, was changed. The lake of fire is called the second death, so if death, prior to Jesus’ return, was characterized by sleep or rest and no man was aware of anything after death, then the opposite would be so when describing the second death / lake of fire. In that place men are conscious both before and after they are cast into this lake or sea. Death, as it was previously understood, escapes them. They have no rest, because they stand in the Presence of God every day, all day, and they are made constantly aware of that Presence. They are forced by the contrast of the Lord’s holiness and their wickedness to face their shame and guilt continually, every day, all day. There is no escape. The question then arises: in such a circumstance (viz. dwelling in the Presence of God), could this ever present awareness change them? I believe it would, and I’ll speak more of this in the next chapter.
 The Book of Life can be likened to a citizen registry, where the names of that city’s citizens are listed. Paul was a citizen of Tarsus (Acts 21:39), meaning his name appeared on that city’s registry. In like manner The Book of Life is a symbol of the citizenship of all the faithful.