11 And [kai] the smoke [kapnos] of their [autos] torment [basanismos] ascendeth up [anabaino] for
[eis] ever [aion] and ever: [aion] and [kai] they have [echo] no [ou] rest [anapausis] day [hemera] nor [kai] night, [nux] who [ho] worship [proskuneo] the beast [therion] and [kai] his [autos] image, [eikon] and [kai] whosoever [ei
tis] receiveth [lambano] the mark [charagma] of his [autos] name. [onoma] KJV-Interlinear
"And the smoke of their torment goes up forever and ever; and they have no
rest day and night, those who worship the beast and his image, and whoever
receives the mark of his name." NASB
The Bible describes a hell, which will go on forever and ever for those who will be cast into it, Rev. 20:10, Isa. 66:24, Dan 12:2, Matt 3:12; Luke 3:17, 2 Thess. 1:9.
Jesus Christ spoke of hell as the place of 'eternal fire,' Matt 18:8; 25:41, of 'unquenchable fire,' Mark 9:43, where 'the fire is not quenched,' Mark 9:48, where it will last forever, Matt. 25:46. For all who reject Christ, heaven will not be an option, and hell will be their certain destiny.
Hell is not a place of social interaction, but one of isolated punishment for each person cast into it. The smoke of their torment is an expression describing an ongoing continuous process of unimaginable anguish, fright, terror, pain, suffering and much, much worse. And, it will last forever.
For those who will live in the Tribulation, that concept will be ignored by many. Most will refuse to believe that there is a place of eternal destruction, even while the world is literally collapsing into tyranny and chaos, all around them.
For seven long years, from the moment following the Rapture, starvation, death, suffering, crime, atrocities, natural disasters and worse, will be constant and unending. With but a couple of pauses between major events, life in the Tribulation will be miserable at best during all of the seven years, and it will get progressively worse during the last three-and-a-half years.
We do not know when the Tribulation is going to occur, because we do not know when the Rapture is going to occur. Therefore we do not know the population of the world in that future date. But many scriptures imply that the population will be huge, because the numbers of martyrs is going to be huge, and the numbers of unbelievers in the world will also be huge. We will see this in the next few verses.
This verse repeats the reason for eternal condemnation, and that reason is because people reject Christ, and in turn favor evil. Furthermore they freely choose the anti-christ, who is the beast, and his policies, and by participating in those policies (all manner of aggression against Jews and Christians in violence and economic ostracism, etc).
And this is supported by their willful acceptance of the mark and image of the beast, and the adoption of evil policies.
The facts of life mandate that repentance is needed. This is a true principle that applies now just as it will in the future. But without doctrine, by rejecting or ignoring doctrine, then people refuse to see their flaws and errors, and that leads to self destruction and worse. You do not want to be caught in that trap.