Conditional Immortality in Scripture?

QUESTION: Do these texts prove the doctrine of conditional immortality: (a) I Tim. 6:16, "Who only hath immortality" and (b) I Cor. 15:53-4, "And this mortal shall have put on immortality."

ANSWER:  (a) "God is said alone to have immortality, because he has it not from another's will, as other immortals have, but from his own essence" (Justin Martyr), "underived, independent immortality" (Wesley's note). (b) This is quoted from a chapter in which the future destiny of the righteous only is described. Paul believed in the resurrection of the unjust (Acts 24:15), as did Daniel in 12:2, and as Christ asserted in John 5:29. But Paul had no occasion to discuss the future of the unjust in this passage. Hence this omission does not disprove their endless existence. Study "eternal punishment" in Matt. 25:46 and Rev. 20:10, where two men "shall be tormented day and night forever and ever."

— From Steele's Answers pp. 31, 32.

Is Immortality Conditional?

QUESTION: Is it true that immortality is conditioned on saving faith in Christ?

ANSWER: Some good people have fallen into this error. When they read annihilation into death and understand life to signify existence, or bare being, instead of well-being, they have a host of Scriptural proof-texts. Whereas there is no word in the Bible meaning annihilation. The Greek word  ἀπόλλυμι (apollumi), destroy, has not that meaning. If it has, we must translate Luke 15:24 thus, "He was annihilated and is found." "I am not sent but unto the annihilated sheep of the house of Israel" (Matt. 15:24). See also Luke 15:4, 6. The destruction of the organism does not destroy the agent for whom it was made. "Fear not them that kill the body, but are not able to kill the soul," etc. The doctrine of annihilation is inseparable from materialism. If the moral Governor of the universe is at last going to rid it of sin by annihilating sinners he would long ago have given assurance of it by annihilating the devil to prevent the spread of this dreadful contagion.

Spirits angelic, satanic and human are indestructible. Hence the infinitude of the divine sacrifice for their redemption.

— From Steele's Answers pp. 30, 31.