Does the Bible teach that the unsaved will suffer in hell for only a time and then be annihilated? Some argue from Scripture that the flames in hell are literal and point out that flames destroy whatever they burn. Further, they claim that infinitely long punishment is disproportionate to a finite life of sin. Thus extinction is morally preferable to everlasting punishment.
The scriptural argument is weak. Clear texts whose explicit intent is to teach the extent of the afterlife overtly compare the everlasting conscious life of the saved and the unsaved (Dn 12:2; Mt 25:41,46). Moreover, the flames in hell are most likely figures of speech for judgment (cp. Heb 12:29; 2 Th 1:8). Otherwise, contradictions about hell are apparent (for example, it is dark despite being filled with flames).
The moral argument fails as well. For one thing, the severity of a crime is not a function of the time it takes to commit it. Thus rejection of the mercy of an infinite God could appropriately warrant an unending, conscious separation from God. Further, everlasting hell is morally superior to annihilation. That becomes evident from the following consideration.
Regarding the end of life, sanctity-of-life advocates reject active euthanasia (the intentional killing of a patient), while quality-of-life advocates embrace it. In the sanctity-of-life view, one gets one's value, not from the quality of one's life, but from the sheer fact that one exists in God's image. The quality-of-life advocates see the value of human life in its quality; life is not inherently valuable. Thus the sanctity-of life position has a higher, not a lower, moral regard for the dignity of human life.
The traditional and annihilationist views about hell are expressions, respectively, of sanctity-of-life and quality-of-life ethical standpoints. After all, the grounds that God would have for annihilating someone would be the low quality of life in hell. If a person will not receive salvation, and if God will not extinguish one made in His image because He values life, then God's alternative is quarantine, and hell is
Thus the traditional view, being a sanctity-of-life and not a quality-of-life superior to annihilationism.
Extracted from the Apologetics Study Bible.