There's a tendency among those defending conditional immortality to use the Old Testament as the lens through which to understand the New Testament rather than the other way around. They will bring up passages like Isaiah 66:24 and point out the fact that although it says that "their worm shall not die," the passages is speaking of "the dead bodies of the men who have rebelled" and state that these people are not suffering conscious torment. However, I would point out that both the rewards of the righteous and the punishments of the wicked as they are portrayed in the Old Testament are but shadows of the reality revealed in the New Testament. Canaan is a picture of heaven but not heaven in its fullness. In Isaiah 65:20, the reward of righteous in the new creation is depicted in such a way that involves extended life but not eternal life. Even the extended life that it prophecies is actually shorter than the lives of some of the Old Testament patriarchs.
Matthew 25:46 speaks of eternal life for the righteous and eternal punishment for the wicked. It would seem that if we are going to read the "eternal life" through the lens of the Old Testament then we would have to conclude that it really just means very long life. Those promoting conditional immortality understand the punishment to be eternal in the sense that the person is eternally unconscious and I when I listened to some of the podcasts from the Rethinking Hell website it often seemed like they were searching through lexicons to find the meaning they wanted. Thayer's was outdated when it was published but I heard them quoting from it in support of their views. However, when you look at a standard lexicon such as BDAG and start working your way through the literature cited that uses this word it's pretty clear that some kind of torture is usually involved not just some judicial verdict with eternal consequences. 4 Maccabees 8:9 speaks of punishing someone through tortures and I think that the fear in 1 John 4:18 is the result of the fear of conscious torture rather than the fear of some judicial verdict. The same word is used in the LXX in Ezekiel 14 and 18 and seems to have the idea of conscious torment associated with it. The verb form of this Greek noun is found in other passages of Scripture and always seems to have the idea of conscious torture.
2 Thessalonians 1:9 is also commonly brought up in the debates and we find those who appeal to conditional immortality appealing to the Old Testament once again. I don't think it's entirely clear whether the eternal destruction is placing the person away from the presence of the Lord or if in fact the unbeliever is experiencing God's destruction in his presence but I do think it's pretty clear that the destruction is ongoing. The destruction is not annihilation. In 1 Corinthians 5:5, Paul hands someone over to Satan to be destroyed in hopes that the person will come to repentance and be saved. The person pretty clearly was not annihilated.
One of the biggest problems in the debate is the use of the word "immortality." "Immortality" literally means to never die. In philosophy, immortality expresses the idea of continual conscious existence. However, in the Scriptures "immortality" is found only in Christ (1 Timothy 6:16, 1 Corinthians 15:53-54). Immortality is not mere conscious existence in Scripture but union with Christ. Also, death in Scripture does not necessarily mean a loss of consciousness. When Adam ate of the tree of the knowledge of good and evil he died. Paul says that in the unregenerate state we were dead in our trespasses and sins. From a scientific perspective we were alive and we maintained conscious existence but we were alienated from God. The Scriptures give the promise that the believer who dies will live but also says that he will never die. Medieval scholastics seem to have imbibed to heavily from Greek philosophy and developed all kinds of ideas about the inherent immortality of the soul but that does not seem to be the case among the early church fathers even though some adopted philosophical language while others did not.
In the following sections I provide quotes and summaries of the teachings of the various church fathers. You can click on the links to read these writings in their totality.
You can find different uses of the word "immortality" among the early church fathers. Some will follow the more Biblical way of speaking and say that only the believer possesses immortality and yet still speak of the unbelievers in eternal conscious suffering. Others will say that both the believer and unbeliever are immortal. Still others, alternate between the two ways of speaking. In seeking to understand what is meant by eternal punishment, I think it is important to consult the early church fathers. The Apostles taught others and I think it's foolish to not take the writings of the early church fathers into account when we interpret these verses. Some simply repeat the language of Scripture, but among those who give further explanation there's a very strong consensus that the unrighteous will suffer eternally and consciously. The only clear exception I could find was Arnobius writings in 305 who spoke of the annihilation of the wicked.
Arnobius was an outspoken critic of Christianity who then converted to Christianity. The local bishop demanded proof that Arnobius and so Arnobius wrote an apologetic work against the pagans. Throughout his work he seems to intend to be orthodox in what he says but lacks a grasp of true Christian doctrine. In this work you can also find him arguing as if the pagan gods are real gods but subordinate to the Biblical God. It's somewhat ironic that those embracing conditional mortality will claim that belief in eternal conscious torment is result of Greek philosophy when Arnobius says that God did not create souls but they were the work of an inermediate being. It seems like Arnobius was pretty heavily influenced by gnosticism.
On the other hand there are host of writings and church fathers that teach eternal conscious torment. The Epistle of Barnabas written between 70-130 speaks of "the way of eternal death with punishment." Justin Martyr writing around 160 says that "Sensation remains to all who have ever lived, and eternal punishment is laid up." Justin Martyr tends to only speak of the righteous as immortal but speaks of the unending torment of the wicked. Tatian writes in 160 and speaks of both the righteous and the wicked as immortal. Athenagoras writing in 175 says that those who fall will endure a life in fire and not be annihilated like animals. Theophilus writing in 180 speaks of people daily burning in fire forever. Clement of Alexandria writing in 195 says that all souls are immortal and says that there is no end to their misery. Tertullian writing in 197 speaks of the "secret fire" of God's judgment and says that it "repairs while it burns" and this is how it is eternal. Tertullian is the first instance I've seen of someone trying to provide some explanation of who the fire burns without annihilating and Tertullian's basic explanation is stated by later writers. Mark Minucius Felix writing in 200 makes very similar statements and speaks of the fire being nourished by the eating away of the bodies and also restoring as it burns. Hippolytus writing in 205 speaks of an unquenchable fire and a fiery worm that "continues bursting forth from the body with unending pain." Origen writing in 225 speaks of the resurrected bodies of the damned as being unable to be dissolved. Origen is known for his speculations that the damned would eventually be reconciled but he never stated this dogmatically. Commodianus writing in 240 speaks of people being tormented in Gehenna for all time. Cyprian does not engage in some of the speculations of others but simply speaks of the eternal punishments of Gehenna when he writes in 250. Lactantius writes some time between 304-313 and specifically says that the souls of the unrighteous are not annihilated but receive everlasting punishment.
This post is not exhaustive in dealing with the issue. Instead it addresses some core issues that don't seem to be addressed in the current debate. The idea of eternal suffering in hell even for your worst enemies isn't a pleasant one. It's hard to imagine being happy while you know that loved ones are suffering eternally. Of course, it's hard to imagine being happy knowing that loved ones were annihilated as well. It's disturbing to contemplate the idea of being born in a completely different location and never hearing the Gospel and then being sent to hell. The Scriptures are clear that we all deserve hell and on a certain level we can confess that to be true but I doubt there's anyone who fully grasps the concept this side of heaven. Scripture is pretty brief on the topic of hell and we don't find anything like "Sinners in the Hands of an Angry God in Scripture." Scripture does not answer all the questions we might have about hell and it's for our own good. There are many secret things of God that are best left unknown to us. Instead, we must not look to the hidden things of God but to God as He has revealed Himself in Christ-crucified where God has revealed Himself in incomprehensible love towards us.
