If you believe in the immortality of the soul, so it would seem, you would have to believe in endless punishment of the wicked or universalism. In the history of the church, belief in the immortality of the soul has been a constant. Not all, but most have believed God made humans immortal. While N.T. Wright, especially in Surprised by Hope and more academically in The Resurrection of the Son of God, has labored to prove that this is not only a later (than the New Testament) belief but also that immortality of the soul is positively not taught in the Bible. Immortality is a gift from God, not an innate possession of humans.
In Rethinking Hell, a chp is included from well-known Reformed evangelical theologian, Philip Edgcumbe Hughes (from his The True Image), where he subjects belief in the immortality of soul to serious re-examination. Calvin, he argues, believed in immortality of the soul but Hughes contends the passages Calvin cites “indicate that the human soul survives physical death,” not that it is inherently immortal.Hughes:
1. The Bible teaches that humans are created/born with the potential of immortality or mortality. Death proves humans are not inherently immortal. The human of the Bible is both body and soul; to make the soul immortal violates biblical unity. The Bible teaches that Jesus gained immortality by virtue of death and resurrection, and that God alone possesses immortality — which is a gift from God. He thinks Calvin’s view is symbiotic: if the saints live forever, the wicked will be punished forever (189).
2. Hughes thinks what God brings into existence, God can destroy. Sodom and Gomorrah is a biblical paradigm for destruction (thus, Gen 18 and Jude 7). The ultimate in the Bible is life vs. death, not punishment and reward. He contends then that the Augustinian view requires that God keeps alive forever the wicked in order to have them dying/dead forever. He sees Augustine as logically confusing in his view of death as eternal, but never finally, dying.
Here is Hughes’s fundamental problem in the logic of ECT: Is it justifiable to call eternal dying “death”?
3. He sees the contrast between eternal life and eternal death to be a comparison of living forever and irreversible death and destruction. He thinks eternal death means obliteration. Immortality is a gift through Christ, not natural to humans. Mutual existence of heaven and hell contradicts the redemption in Christ. It means eternal existence of alienation and rebellion and therefore the incompletion of the victory. [I find this argument one of the most persuasive elements of conditionalism.] The second coming of Christ will put death to all death.