The Devil's Fate

Demons are not humans.  They are not said to be especially made in God's image, though they would be necessity share some characteristics with God, like consciousness and intellects and intentionality within their minds.  They are the beings Jesus says hell was created for (Matthew 25:41), suggesting that they were created prior to humans.  This is relevant to the fact that Revelation says that the devil, the beast, and the false prophet will be tormented day and night forever and ever (20:10), though it not only does not say the same about the humans thrown into the lake of fire (20:11-15), but humans suffering eternally would contradict everything the Old Testament and New Testament say about the punitive afterlife that awaits the wicked--with the initially seeming exception of people who have taken the mark of the beast (Revelation 14:9-11); the smoke of their torment literally rising forever would still not require that they exist forever.

Is Revelation 20:10 literal, though?  While the Bible simply makes the promise that the second death, with its permanent extinction of consciousness, will be the just outcome for the human unsaved, even for the Satan, it would be true in his case that finite sins would be punished with infinite torment if Revelation 20:10 is literal.  The only explicit reference to eternal conscious torment in the Bible is the book that is sometimes the most figurative, and the only possible, hyperbolic reference to eternal conscious torment for humans exclusively involves those who take the mark of the beast; neither case, however, would contradict the Biblical claim that the collective unsaved of humanity are destined for eternal death after very limited torment, if any at all.

While it is not actually established if the fallen angel of Ezekiel 28 is what the New Testament calls "the devil," this demonic entity is possibly the same being.  At the very least, this chapter refers to a specific, singular angel of particular beauty that descends into arrogance and sinful violence, initially falling into pride because of its great beauty (28:17).  Ezekiel 28 states what the fate of this being is: to be consumed with fire and burnt to death (28:18), to "be no more" (28:19).  If this is Satan, then long before Revelation was written, God had already revealed what is supposed to await this demon who once walked in Eden as a guardian cherub (28:13-14).  The passage shifts either way from references to a human monarch, the king of Tyre, to a clearly demonic but unnamed being said to at some point be killed by fire.

It is indeed true that some things in Revelation are plainly symbolic.  Some verses clarify this as they describe the literal reality that a figurative image or word points to, so there is always a necessary element of sheer literalism.  It is entirely possible that Revelation 20:10 is not literal after all when it says that the devil and at least two others will be tormented without end, but it is also possible that the fallen cherub of Ezekiel 28 that will come to an end by fire is not Satan, the devil, at all, just a different demon.  At the same time, the differences between demons and humans mean that hell was not made for the latter, and the very obvious, constant justice in store for wicked/unsaved humans is an end to their conscious existence altogether through cosmic death (Ezekiel 18:4 and Matthew 10:28 alone establish this).

Again, the issue of the massive disparity between endless torture for sin and a finite number and severity of sins committed would arise with the devil's fate.  Justice is justice regardless of the being it is inflicted upon.  Although the aforementioned distinctions between fallen angels and fallen humans are still there in Biblical philosophy, it is not as if injustice becomes just depending on who it is directed towards.  This needs to be recognized even when it concerns Satan, perhaps identical with the corrupted cherub of Ezekiel 28 that is certainly said to not be tortured forever.  Even if the devil was a liar from the beginning of his fall and a murder (John 8:44), unsaved murderers do not have eternal life (1 John 3:15), the eternal existence that no being but God has by default (1 Timothy 6:16) and that God and Christ must extend to humans, without which one would cease to exist for one's sin.  Satan himself would very well also be destined for death, for destruction, not for eternal torment.