Universalists sometimes claim that punishment in hell is restorative. They use Matthew 25:46 as a proof-text and translate kolasin aiōnion (κόλασιν αἰώνιον) as agelong chastening or correction. Below I list four reasons why I do not believe in restorative punishment in hell.
First, the noun kolasis (κόλασις) only occurs two times in the NT (Matt. 25:46; 1 Jn. 4:18) and the verb kolazó (κολάζω) also only occurs two times in the NT (Acts 4:21; 2 Pet. 2:9). The majority of English translations translate Kolasis and kolazó as “punish,” “punishment,” or “torment,” (see KJV, NIV, NLT, ESV, NASB, HCSB, NET Bible). In fact, Francis Chan “checked ten commentators from different theological backgrounds and fifteen Bible translations in five different languages on the word kolasis… they all translate kolasis with the word ‘punishment.’”
Second, the term kolasis is used by other literature of the period to mean (non-restorative) punishment. For example, Josephus talks about Herod being on trial and in danger of being sentenced to death, but through the intervention of the high priest, he was delivered from that danger, and all punishment (kolaseōs) (Josephus, Antiquities XV, 16). “Punishment” in the case above does not seem to be used in the “pruning” sense because he is being saved from death (cf. e.g. 2 Macc. 4:38; 4 Macc. 8:9-11). Further, BDAG, one of the most respected dictionaries of Koine Greek, lists all sorts of examples where kolazó and kolasis means “punish” or “punishment” in the non-restorative sense. TDNT also a widely respected dictionary says that the meaning of kolasis is “punishment” and the meaning of kolazó is “punish.”
Third, there are other terms that the NT uses to refer to the concept of punishment. Apollumi (ἀπόλλυμι) occurs ninety-two times and means to “destroy” (e.g. Matt. 10:28; 21:41). Olethros (ὄλεθρος) occurs four times and it means “destruction” (see 2 Thess. 1:9). Timória (τιμωρία) occurs just one time and means “punishment” or “vengeance” (see Heb. 10:29). Ekdikésis (ἐκδίκησις) occurs nine times and means “vengeance” (see 2 Thess. 1:8). Orgé (ὀργή) means “wrath” (see Rom. 2:5; Rev. 14:10) and occurs 36 times. William V. Crockett, a graduate of Princeton Theological Seminary and University of Glasgow, has said, “when we examine orge in Paul we find no reason to assume that it has reformative elements.” He goes on to say, “orge in Paul excludes any notion of divine love.”
Fourth, there is a lot of imagery in Scripture of God’s wrath being poured out that does not look like restorative punishment. This is the type of imagery we see: “So the angel swung his sickle across the earth and gathered the grape harvest of the earth and threw it into the great winepress of the wrath of God. And the winepress was trodden outside the city, and blood flowed from the winepress, as high as a horse’s bridle, for 1,600 stadia [i.e. about 184 miles]” (Rev. 14:19-20 see also Ps. 110:5-6; Is. 66:24; Ezek. 39:17ff; Matt. 24:51; Rev. 6:15-17; 19:11ff; 20:11ff; 21:27).
Revelation 14:11 emphatically says, “the smoke of their torment goes up forever and ever, and they have no rest, day or night.” Revelation 20:10 says, “The devil who had deceived them was thrown into the lake of fire and sulfur where the beast and the false prophet were, and they will be tormented day and night forever and ever.” Matthew 3:12 talks about “unquenchable fire.” Mark 9:48 says the “worm does not die and the fire is not quenched” (cf. Is. 66:24).
Also recall that it is those who “conquer” in space and time who can eat from the tree of life and who will not be touched by the second death (Rev. 2:7, 11). It’s the one who conquers on earth before the Final Judgment that has a “white stone” as admission to heaven (2:17). So we see in Revelation that there seems to be a clear and decisive end to the chance that people have to repent. The one who conquers is the one “who keeps my works until the end” (v. 26). It is those who conquer on earth before the coming of the Lord Jesus that will be dressed in white garments and have their names in the book of life (3:5).
So, upon looking at the evidence, it seems clear to me that punishment in hell is gravely not restorative, but retributive. Understood in this way I believe we can better make sense of Jesus’ parallelism in Matthew 25:46, everlasting punishment on the one side and everlasting life on the other. We also find ourselves in line with what seems to be the Jewish (or at least pharisaical) expectation of the time.
 Rob Bell incorrectly says that the verb kolazo is used in Matthew 25:46; however, it is not, the verb form kolasis is. He then argues that the verb kolazo “is a term from horticulture. It refers to the pruning and trimming of the branches of a plant so that it can flourish” (Love Wins, 91).
 Francis Chan, Erasing Hell, Kindle Locations 1072-1074.
 Notice that Josephus overlaps with the timing of the NT (circa 37-100). Also, 2 Clement 6:7 says, “For, if we do the will of Christ, we shall find rest; but if otherwise, then nothing shall deliver us from eternal punishment [αιωνιου κολασεως], if we should disobey His commandments” (cf. Martyrdom of Polycarp 11:2).
 BDAG (A Greek-English Lexicon of the New Testament and Other Early Christian Literature is known as “BDAG” for the names of the editors Bauer, Danker, Arndt and Gingrich).
 J. Schneider, “kolazó, kolasis,” in The Dictionary of the New Testament, ed. Gerhard Kittel, trans. Geoffrey W. Bromiley, vol. 3 (Grand Rapids: Eerdmans, 1965), 814-17.
 Realize this is referring to koine or biblical Greek and not all Greek throughout history. For instance, Aristotle (384-322BC) spoke Classical Greek whereas the NT (completed c. 90AD) is written in a latter more common form of Greek. Words change over time. We could give various examples but the word “gay” is one that comes to mind. However, the literature around the time of the NT shows that kolasis and kolazó are not used to communicate the idea of restorative punishment.
 From the root τιμωρέω; see Acts 22:5; 26:11.
 See William V. Crockett, “Wrath That Endures Forever,” in JETS 34/2 (June 1991) 195-202.
 Ibid., 198.
 Ibid., 199.
 I believe we see the decisiveness of this life all over the NT. And even other literature of that period. For example, the Didache says, “There are two ways, one of life and one of death, and there is a great difference between the two ways” (1:1).
 Josephus says “the Pharisees are those who are esteemed most skillful in the exact explication of their laws” (The Wars of the Jews, II. 162) and “they say that all souls are incorruptible; but that the souls of the good men are only removed into other bodies, –but that the souls of bad men are subject to eternal punishment” [aidiōi timōriai kolazesthai]” (The Wars of the Jews, II.163) Josephus was himself a Pharisee and so he would have known their perspective on judgment. See also: Dan. 12:1-3; 1 Enoch 90:26-30; 4 Ezra 7:32-8:2; 2 Baruch 51:2, 6; 85:8-86:1; 4 Macc. 9:8; 10:11, 15; 12:12; 13:15; Judith 16:17; Ecclesiasticus 7:16-17.