Those who hold to conditional immortality maintain that only God has immortality (natural eternal existence) and that the only other ones who receive immortality are those who are given it; namely, Christians. The wicked are annihilated either right after death or sometime afterward having completed a time of punishment.

• “What conditionalists point out, however, is that eternal life in all of its verbal expressions— and in particular when it is described in terms of “immortality”— is exclusively promised as a gift to those who are saved through Christ.”¹ Rethinking Hell: Readings in Evangelical Conditionalism (Kindle Locations 593-595). Cascade Books, an Imprint of Wipf and Stock Publishers. Kindle Edition.
• “Immortality is a state gained by grace through faith when the believer receives eternal life and becomes a partaker of the divine nature, immortality being inherent in God alone.”²Morgan, Christopher W.; Peterson, Robert A.. Hell Under Fire: Modern Scholarship Reinvents Eternal Punishment (Kindle Locations 475-476). Zondervan. Kindle Edition.

Now, we have to be clear here. The phrase “eternal life” is only used of believers. But for the conditionalist to say that only the redeemed will live forever is wrong. Jesus taught that angels also live forever.  This would mean then that the conditionalist view that “immortality is exclusively promised as a gift to those who are saved through Christ” is not correct.

Luke 20:34–37, “Jesus said to them, ‘The sons of this age marry and are given in marriage, 35 but those who are considered worthy to attain to that age and the resurrection from the dead, neither marry nor are given in marriage; 36 for they cannot even die anymore, because they are like angels, and are sons of God, being sons of the resurrection. 37 But that the dead are raised, even Moses showed, in the passage about the burning bush, where he calls the Lord THE GOD OF ABRAHAM, AND THE GOD OF ISAAC, AND THE GOD OF JACOB.'”  

As you can see in the scriptures (see the underlined above), Jesus said that angels do not die.  The context is when he was speaking to the Sadducees who had raised a challenge to him about the future resurrection. Jesus responded, corrected them, and added this tidbit of information that is so useful here.  He said that those in the resurrection “cannot die anymore, because they are like angels.”

If the conditionalists are correct and only Christians are given immortality (will live forever), then why does Jesus say the angels cannot die?  It appears that they also have immortality as part of their nature.

• “They are equal to angels, or, specifying the point of comparison, ‘they exist like angels’, ‘they live on like angels do’.”³Reiling, J., and J. L. Swellengrebel. A Handbook on the Gospel of Luke. UBS Handbook Series. New York: United Bible Societies, 1993.
• “Jesus did not say that resurrected people become angels. His point was that they, like angels, will be immortal. Thus there will be no further need for procreation, and the marriage relationship will not be necessary.”⁴Walvoord, John F., and Roy B. Zuck, Dallas Theological Seminary. The Bible Knowledge Commentary: An Exposition of the Scriptures. Wheaton, IL: Victor Books, 1985.
• Luke adds to Mark’s account in vv. 35–36 the worthy are raised; they cannot die any more; they are equal to (not “like”) angels; they are children of God.”⁵Mays, James Luther, ed. Harper’s Bible Commentary. San Francisco: Harper & Row, 1988.
• “they are like the angels” Notice that the context is emphasizing, not sexlessness, but the state of immortality.”⁶Utley, Robert James. The Gospel according to Luke. Vol. Volume 3A. Study Guide Commentary Series. Marshall, TX: Bible Lessons International, 2004.
• “equal to the angels = (or) similar to angels (preferable, as the point is eternality, and regenerate saints will be superior to angels [1 Cor 6:3]).⁷Mills, M. S. The Life of Christ: A Study Guide to the Gospel Record. Dallas, TX: 3E Ministries, 1999.

I’ve cited five commentaries that teach that this passage affirms the immortal nature of angels. But, just because we have five who say the same thing, it doesn’t mean that’s proof of the error of conditionalism regarding the mortality being a quality of God alone and those who are redeemed in Christ. But still, in my research, I did not find a single commentary that contradicted the idea that the angels don’t die.

Furthermore, the plain reading of the Scripture is consistent with the idea of the eternal nature of angels. Various translations say the same thing.

• NASB, “for they cannot even die anymore, because they are like angels”
• ESV, “for they cannot die anymore, because they are equal to angels”
• NIV, “and they can no longer die; for they are like the angels”
• NRSV, “Indeed they cannot die anymore, because they are like angels”
• KJV, “Neither can they die any more: for they are equal unto the angels”

So, angels don’t die.  They live forever.

One response from a conditionalist could be that angels don’t die biologically, but that they (the wicked angels) do die by being annihilated.  But this interpretation contradicts what Jesus said:  “they cannot die anymore, because they are like angels.”  Nothing in His words specify a restriction to only good angels.

Let’s take a look at the Greek.

for	they cannot even	die	anymore	because	they are	like angels	and	are	sons	of God
γάρ	οὐδὲ δύνανται	ἀποθανεῖν	ἔτι	γάρ	εἰσιν	ἰσάγγελοι	καί	εἰσιν	υἱοί	θεοῦ
gar	oude dunantai	apothanein	eti	gar	eisin	ἰσάγγελος	καί	eisin	huioi	theou

This isn’t rocket science. “Oude dunanatai” is a phrase of strong negation. It is saying it is not possible.  “oude” is the negator:  not, cannot.  “δύνανται” means ability, power.

• “Oudé is continuative, meaning and not, also not, and hence, not, neither, not even, usually as connecting whole clauses or propositions.”⁸Zodhiates, Spiros. The Complete Word Study Dictionary: New Testament. Chattanooga, TN: AMG Publishers, 2000.
• “οὐδέ oude; from 3756 and 1161; and not, neither:—all(2), cannot*(3), either(4), even(37), neither(4), no(4), no*(1), nor(64), nothing*(1), or(20), then(1).”⁹Thomas, Robert L. New American Standard Hebrew-Aramaic and Greek Dictionaries : Updated Edition. Anaheim: Foundation Publications, Inc., 1998.

This phrase “οὐδὲ δύνανται”, “oude dunantai” occurs nowhere else in the New Testament.  It is clearly showing the impossibility, the inability.

Conclusion

Jesus taught that angels live forever (Luke 20:36). They have immortality.  No differentiation is made between good or bad angels.  This would mean that the conditionalists’ position which states that “immortality is exclusively promised as a gift to those who are saved through Christ,” is not correct (underline added).  Therefore, the conditionalists need to reassess their position and adjust it according to Scripture.