Answer: See below. But before you scroll down, let's interact with two practical and preparatory concerns.
1) Why does the question matter?
2) What are the possible theological and scriptural alternatives?
After a brief overview we should then be able to consider the biblical case for conditional immortality.
Why does the question matter?
Hell's been getting a bum wrap. In either of two ways. On one extreme, it is being ignored. For many years now churches and preachers have been shying away from the topic because it is uncomfortable to talk about. After all, who enjoys contemplating and discussing an eternity of pain and suffering? But hell is also often neglected because many sensitive Christians are worried that a steady diet of hellfire and brimstone can make God look like a sadistic ogre. As believers we don't want to unnesessarily push people away from Jesus Christ.
This is a valid concern and is actually the other extreme that is giving hell a bad reputation. Some fundamentalists, who are not shy when it comes to preaching eternal damnation, in their zeal often overstate the case and actually mistakenly proclaim that God takes pleasure in the demise of the wicked. As a result, effective evangelism suffers.
So as to why this question matters: Understanding the nature of hell is important because the effectiveness of evangelism is at stake. On the one hand, we don't want to lose our urgency to witness to lost friends and family by being nonchalant about hell. A person's eternal life is hanging in the balance. Yet on the other hand, we don't want to run the risk of turning people off by misrepresenting a doctrine that is already a sticking point for many.
What are the possible scriptural alternatives?
So what are some possible views on hell? How are we to understand this hard teaching? One response is to abolish it by trying to make a biblical case for universalism. That is, ultimately all will be saved. This is not just a "liberal" attempt at downplaying a distastful teaching. It stems from Origen, an early church father, who viewed hell as "a purging and refining fire that finally deposits all its inhabitants in heaven." (Pinnock, p 141) Hell is a temporary but real condition that takes the offense of sin seriously while affirming God's ultimate victory over it. Scripture texts include John 3:16, Philippians 2:10,11, and 1 Timothy 2:3,4.
A problem stems from the possibility that all may not want to be saved. That may be God's intent, but can God predestine a person's free response to his grace? That doesn't make sense. While I affirm that God's salvation is by grace alone, it is also through faith alone. And while even faith is a gift, we must respond. If we reject God, God will honor our request. (This issue involving predestination is too broad to be covered here. Suffice it to say that if asked, "Were you pushed or did you jump?" I'd have to answer yes.)
A second possibility is the traditional, or what some may call the literal, view of hell. This teaching was developed by Augustine, another early church theologian, who in The City of God
What? How does Augustine come to a biblical conclusion that God is a God that tortures people forever? His literal reading does an injustice to the plain implications of the words employed. Far be it from me to enter the ring against such a heavyweight theologian, nevertheless, might it be that, like his doctrine of the millennium or the practice of infant baptism, Augustine got this one wrong as well?
A third view is a revision of the traditional position. Instead of physical pain caused by actual flames, the suffering is mental and emotional. Here the fire is simply a metaphor. And although some might want to entertain as more palatable the notion expressed in Jean-Paul Sartre's No Exit
More importantly, is this really what the scripture means when it refers to hell?
So now we turn to the biblical case for conditional immortality, or as some refer to it, annihilationism. I want to address two main issues: The clear implications of the words used to describe hell and the biblical understanding of the nature of the soul.
Certainly hell is a real reward for the wicked. As Christians we must engage God's word on the matter. But as to it's exact nature, I agree with Clark Pinnock who writes (far better than I):
From the threat of hell, we may not be able to derive precise knowledge about its nature, any more than we can grasp the nature of heaven from the promises God gives us regarding it. Nevertheless, the Bible does leave us a strong general impression in regard to the nature of hell - the impression of final, irreversible destruction, of closure with God. The language and imagery used by Scripture is so powerful in that direction that it is surprising that more theologians have not picked up on it before now. The Bible uses the language of death and destruction, of ruin and perishing, when it speaks of the fate of the impenitent wicked. It uses the imagery of fire that consumes whatever is thrown into it; linking together images of fire and destruction suggests annihilation. One receives the impression that "eternal punishment" refers to a divine judgment whose results cannont be reversed rather than to the experience of endless torment (i.e., eternal punishing). Although there are many good reasons for questioning the traditional view of the nature of hell, the most important reason is the fact that the Bible does not teach it. Contrary to the loud claims of the traditionalists, it is not a biblical doctrine. (p 144)This essay has gone on longer than expected, so I will probably examine some key scriptural texts in the Q & A to follow (if there is any :-) . But a sampling includes Matthew 3:10-12, 13:49,50; Romans 6:23; 1 Corinthians 3:17, Galatians 6:7,8; Philippians 1:28; 2 Thessalonians 1:9; Hebrews 10:39; 2 Peter 3:7; Jude 7; Revelation 20:14,15. A fair reading of these passages can lead to a reasonable conclusion that the bible teaches the final destruction of the wicked. This is not a dumbing down of the scripture but an interpretation that is plausible and has integrity.
Let me briefly address a second issue and wrap this up. And this has to do with why the traditional view is so entrenched as "the" evangelical option today. It has to do with a mistaken understanding of human nature. A hellenistic belief about the immortality of the soul "has dominated Christian thinking about eschatalogy almost from the beginning." (Pinnock, p 147) In other words, the bible does not teach the inherent immortality of the human soul. Rather it points to the resurrection of the body as God's gift to believers. God alone is immortal. We are conditionally so. We acccept eternal life and enter into an eternity with God. Those who reject this offer can not enter into eternal life. Their fate is seperation from God forever. Hell.
Hell does have a fury. It will be unleashed on those who are impenitent. It is a permanent, irreversable state. Hell is a doctrine that is sobering and shocking to contemplate. And one which begs for an urgent response. We can no longer neglect the teaching of hell, nor can we afford to mistakenly assign God's pleasure to the torturing of his creation. Let the message of hope and salvation overcome our hesitancy to proclaim the full gospel of Jesus Christ.
(For more information on Clark Pinnock.)