‘kairos’ G2540; Of uncertain affinity; an occasion, that is, set or proper time: – X always, opportunity, (convenient, due) season, (due, short, while) time, a while. Compare G5550.
‘chronos’ G5550; Of uncertain derivation; a space of time (in genitive case, and thus properly distinguished from G2540, which designates a fixed or special occasion; and from G165, which denotes a particular period) or interval; by extension an individual opportunity; by implication delay: – + years old, season, space, (X often-) time (-s), (a) while.
‘aionios’ G166; From G165; perpetual (also used of past time, or past and future as well): – eternal, for ever, everlasting, world (began).
There’s a doctrine that has roots in ancient Universalism, which in short states that all people, regardless of their state at death, will eventually be ‘saved.’ Some believe this includes even Satan and the fallen angels. The doctrine teaches that everlasting and eternal don’t mean life without end, thus those in Christ will live long but not forever. This is based upon the meaning of the word ‘aionios’ which is claimed means ‘of limited duration’ but there’s nothing in it’s definitions to suggest this. However, it’s root ‘aion’ can mean a time of limited duration, but not always, and only where the CONTEXT of the passage supports it. From the same as G104; properly an age; by extension perpetuity (also past); by implication the world; specifically (Jewish) a Messianic period (present or future): – age, course, eternal, (for) ever (-more), [n-]ever, (beginning of the, while the) world (began, without end). As you can see, only the first definition, ‘an age’ may suggest a time of limited duration. The others; ‘perpetuity’ ‘eternal’ ‘forever’ and ‘world without end’ suggest the opposite. Let’s look at one other word ‘aei’ from which ‘aion’ is derived – ‘aei’ (G104) From an obsolete primary noun (apparently meaning continued duration); “ever”; by qualification regularly; by implication earnestly: – always, ever. Thus ‘aei’, the root of ‘aion’ which is the root of ‘aionios, doesn’t have even a hint of temporary or limited, in it’s definition. The claim that ALL men, whether they repent or not, will eventually be “reconciled” back to God is based upon a handful of Scriptures, in particular Col 1:20 – “And having made peace through the blood of his cross, by him to reconcile all things unto himself; by him, I say, whether they be things in earth, or things in heaven.”
If ‘all things’ means unrepentant sinners, Satan, and devils, then how do you explain the following?
Heb 6:4 For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
Heb 6:5 And have tasted the good word of God, and the powers of the world to come,
Heb 6:6 If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
If those who “fall away” (apostacize) from the Faith CANNOT be restored, then how can the Devil, Satan, and the fallen angels, and unrepentant sinners be ‘reconciled’ back to God? Scripture is clear that Satan, the False Prophet, and the Beast, along with all the unrepentant who worshiped them, will be “cast into the Lake of Fire” which Scripture calls the “second death.” The first death is dying physically – “It is appointed unto man to die once, and then the JUDGMENT.” (Heb 9:27) Note that the word “judgment” (Gk ‘krisis’ from which the word ‘crisis’ came) means ‘separating, sundering, selection, decision, accusation, condemnation, damnation, and punishment.’ I would indeed call damnation a crisis! Notice that the “lake of fire” is not hell or hades, the place where souls go to wait for the Judgment. Hell or Hades, is not a place of punishment and torment. However, the “lake of fire” IS, and is the place where all those not found written in the BOOK OF LIFE will go. We know this because Rev 20:15, says so. (See Rev. 19:20, 20:10, 20:14 & 15)
Rev 20:10 states that they will be “tormented” there, “day and night, for ever and ever.”
“forever and ever” G165 “aion-aion”
1) for ever, an unbroken age, perpetuity of time, eternity
2) the worlds, universe
3) period of time, age
Perpetuity, unbroken age, eternity – all mean basically the same thing; time without end. How clever Satan is, to try and wipe out the clear message of Scripture by causing confusion about the meaning of ‘aion’ and ‘aionios’ thereby reducing the PROMISE of life unending for believers, and of unending PUNISHMENT for the Wicked. The Devil and fallen angels would like for us to believe that they aren’t so bad after all, and that Satan was really a VICTIM of injustice on God’s part, so God MUST pardon him and all the wicked, or else He’s UNJUST right? Sounds like a “doctrine of devils” as they continually accuse God of injustice, unfairness, cruelty, etc. Satan and his angels know very well that their DAMNATION is coming and that it is JUST. They beheld God in Heaven with their own eyes – what excuse have they for ‘falling away?’
Here’s something else to think about. How does believing that God will reconcile the wicked back to Him in the end, give sinners incentive to turn to Christ and live in self-denial, when they can “live it up” now and still get saved later? Is it fair to those who love and serve God with all their hearts, purifying themselves, and denying themselves if those who live careless, selfish, and sinful lives, end up in God’s Kingdom just the same? And what of witnessing to the LOST if they’re not really lost after all? If all get saved in the end, why witness at all? Jesus said that He came to “seek and to save the lost.” If the LOST aren’t really lost, then why did Jesus have to seek for and save them? Save them from what?
Who will be ‘saved’ or reconciled back to God, and be allowed to enter into His Kingdom?
Mat 7:21 “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven.
Is Satan doing the will of the Father? Are sinners?
Mat 10:32 So everyone who acknowledges me before men, I also will acknowledge before my Father who is in heaven,
Mat 10:33 but whoever denies me before men, I also will deny before my Father who is in heaven.
Do wicked sinners acknowledge God? Hardly. At best, they rarely give Him a thought, and most oppose Him at every opportunity.
Mat 25:31 “When the Son of Man comes in his glory, and all the angels with him, then he will sit on his glorious throne.
Mat 25:32 Before him will be gathered all the nations, and he will separate people one from another as a shepherd separates the sheep from the goats.
Mat 25:33 And he will place the sheep on his right, but the goats on the left.
Mat 25:34 Then the King will say to those on his right, ‘Come, you who are blessed by my Father, inherit the kingdom prepared for you from the foundation of the world.
Mat 25:35 For I was hungry and you gave me food, I was thirsty and you gave me drink, I was a stranger and you welcomed me,
Mat 25:36 I was naked and you clothed me, I was sick and you visited me, I was in prison and you came to me.’
Mat 25:37 Then the righteous will answer him, saying, ‘Lord, when did we see you hungry and feed you, or thirsty and give you drink?
Mat 25:38 And when did we see you a stranger and welcome you, or naked and clothe you?
Mat 25:39 And when did we see you sick or in prison and visit you?’
Mat 25:40 And the King will answer them, ‘Truly, I say to you, as you did it to one of the least of these my brothers, you did it to me.’
Mat 25:41 “Then he will say to those on his left, ‘Depart from me, you cursed (G2675 ‘doomed’), into the eternal fire prepared for the devil and his angels.
Mat 25:42 For I was hungry and you gave me no food, I was thirsty and you gave me no drink,
Mat 25:43 I was a stranger and you did not welcome me, naked and you did not clothe me, sick and in prison and you did not visit me.’
Mat 25:44 Then they also will answer, saying, ‘Lord, when did we see you hungry or thirsty or a stranger or naked or sick or in prison, and did not minister to you?’
Mat 25:45 Then he will answer them, saying, ‘Truly, I say to you, as you did not do it to one of the least of these, you did not do it to me.’
Mat 25:46 And these will go away into eternal punishment, but the righteous into eternal life.”
A Concise Look at the Nature and Duration of Hell
Many Christians and non-Christians alike downplay the biblical presentation of God’s wrath for the unregenerate and their final abode in hell—namely, “everlasting punishment.” The Universalists or Inclusivists, and groups like the Seventh-Day Adventists and Jehovah’s Witnesses boldly reject the “biblical doctrine” of hell. While this doctrine can be quite difficult to comprehend and thus, accept, biblical doctrine is not determined by emotion or philosophy, but rather by the exegesis of the text. God’s Word is true regardless whether one accepts or rejects it (cf. 2 Tim. 3:16).
The Nature of Hell
The biblical authors used many terms to describe the final abode of unregenerate, e.g., “hell,” “Hades,” “the lake of fire,” “black darkness,” “eternal punishment,” “eternal flame/fire,” “eternal destruction” (cf. Matt. 18:8; 25:46; 2 Thess. 1:9; Jude 7, 13; etc.). Mt 25:46 reads, “And these will go away into eternal [aio-nion] punishment, but the righteous into eternal [aio-nion] life.” The term “punishment” is from the Greek word, kolasin, which *recognized* lexicographers define (in first cent. Koine-Greek) as “punishment” /”chastisement” (e.g., Thayer, BDAG, et al). Revelation 20:10 reads, “And the devil who deceived them was thrown into the lake of fire and brimstone, where the beast and the false prophet are also; and they will be tormented day and night forever and ever.” The word “tormented” is from the Greek word basanizo, which is defined by Thayer as “being vexed with grievous pains.” Basanizo is also used in Luke 16:23 and, as discussed below, Revelation 14:11 and 20:10. In contrast to the doctrine of Annihilationism, logically one must be awake or conscious to actually experience or (as these texts above plainly indicate) receive “punishment” and “torment” (i.e., being “vexed with grievous pains”). Annihilationism teaches that when the wicked die they are totally destroyed ceasing to exist—however, a person that does not exist cannot be punished or feel anything such as torment.
The Duration of Hell: Aio-n, Aio-nios
Eternal fire for the unregenerate is a biblical reality. Jesus said it was. It was for this reason that Jesus died (cf. Rom. 5:8-10). Those who are not imputed with the righteousness of Christ through faith in Him, will be cast out into hell where they will endure eternal punishment: “And these will go away into eternal punishment, but the righteous into eternal life” (Matt. 25:46). Here the word “eternal” (aio-nion) is used BOTH to describe the DURATION of life that believers will have and the “punishment” (kolasin) that the unregenerate will undergo—thus, the punishment is endless just as the “eternal life” is endless for believers. Commenting on this passage (viz. on the phrase, kolasin aio-nion, “eternal punishment”), renowned Greek scholar A. T. Robertson states: “[aionios] comes as near to the idea of eternal as the Greek can put it in one word.”
Those that deny the never-ending duration of God’s wrath (hell) do so primarily on emotional grounds (e.g., distorting the love of God) and a faulty understanding of the Greek terms aio-n (“age”) and aio-nios  (“eternal”/“everlasting”). The Greek word aio-nios is from the root word aio-n meaning “age.” The Universalists and others who deny the never-ending duration of hell point out that the term aio-nios does not always mean “eternal,” but can refer to a temporary or finite period of time. However, note the following details –
CONTEXT determines meaning. Words are defined by their context. It is a great error in hermeneutics to limit words to one meaning when they may have multiple meanings as with the majority of Greeks words—it always depends on the context. It is true that the term aio-nios can be used to indicate a temporary non-eternal state (as in Rom. 16:25). However, just because the root (aio-n) of the term aio-nios means “age” it does not mean that every time the term is used it indicates temporality. For example, Paul uses aio-nios to describe God’s eternal nature: “who alone possesses immortality and dwells in unapproachable light; whom no man has seen or can see. To Him be honor and eternal [aio-nion] dominion! Amen” (1 Tim. 6:16). It would be heresy to translate aio-nion here in a temporal sense making God’s dominion temporary—for His sovereignty is everlasting.
Lexical Support. The lexical support for aio-nios as denoting the concept of eternal/everlasting life for the believer in passages such as John 3:16; 6:47; 10:28; etc. is unquestionable. Equally, the lexical support for aio-nios as denoting the concept of eternal/ everlasting damnation in passages such as Matthew 25:41, 46; 2 Thessalonians 1:9; Revelation 14:11; 21:10; etc. is indisputable. Aside from passages where aio-nios means “eternal” life (as seen above) and denoting God’s eternal nature (e.g., Rom. 16:26), Vine’s Expository Dictionary of Biblical Words (1985) states: “Aio-nios is also used . . . of the judgment of God, from which there is no appeal, Heb. 6:2, and of the fire, which is one of its instruments, Matt. 18:8; 25:41; Jude 7, and which is elsewhere said to be ‘unquenchable,’ Mark 9:43. The use of aio-nios here shows that the punishment referred to in 2 Thes. 1:9, is not temporary, but final. . . .”
Below are brief excerpts taken from one of the most utilized and scholarly lexicons, Walter Bauer’s, A Greek English Lexicon of the New Testament (BDAG), which provides a most comprehensive analysis of aio-nios regarding the “everlasting” duration of both life and damnation (hell): “aio-n formulaically= eternal [Rev.] 14:11; 19:3; 20:10; 22:5. . . . aio-nios “without beginning or end; of God (Gen 21:33; Is 26:4). . . . Very often of God’s judgment [Jer 23:40; Da 12:2; Ps 76:6; Mt 18:8; 25:46; Mk 3:29; 2 Co 6:7; 2 Th 1:9; Jd 7]. . . . pert. to a period of unending duration, without end. . . .” (32-33). Therefore, besides the passages that clearly (from the context) denote a temporary significance (e.g., Rom. 16:25), the lexical support (e.g., Thayer; Louw and Nida; Liddell and Scott; BDAG, et al) for aio-nios as denoting eternal, endless duration is conclusive.
The New Testament Usage of the Aio-nion
Note the following examples of where aio-nios is used to denote the everlasting duration of life with the Lord for the believer –
John 6:47 – “Truly, truly, I say to you, he who believes has eternal [aio-nion] life”; 10:28: “and I give eternal [aio-nion] life to them, and they shall never perish. . . .” (see also Acts 13:48; Rom. 2:7; 5:21; 16:26; Gal. 6:8; 1 Tim. 6:16; etc.). Now observe the following examples of where aio-nions is used to denote the everlasting punishment for the unregenerate – Matthew 18:8 “And if your hand or your foot causes you to stumble, cut it off and throw it from you; it is better for you to enter life crippled or lame, than having two hands or two feet, to be cast into the eternal [aio-nion] fire”; 25:46: “And these will go away into eternal [aio-nion] punishment, but the righteous into eternal [aio-nion] life”; 2 Thessalonians 1:9: “And these will pay the penalty of eternal [aio-nion] destruction, away from the presence of the Lord and from the glory of His power” (see also Matt. 25:41; Mark 3:29; Luke 18:30; Jude 7; Rev. 14:11; 20:10 [as discussed below] where aio-nios represents eternal damnation).
Does the phrase “forever and ever” mean endless?
The phrase “forever and ever” (aio-nas to-n aio-no-n, lit., “ages of the ages”) is used to express God’s eternal significance and the everlasting “torment” for the unregenerate.
1 Timothy 1:17: “Now to the King eternal [aio-no-n], immortal, invisible, the only God, be honor and glory forever and ever [aio-nas to-n aio-no-n]. Amen.”
Revelation 5:13: “To Him who sits on the throne, and to the Lamb, be blessing and honor and glory and dominion forever and ever [aio-nas to-n aio-no-n].”
Revelation 14:11 “And the smoke of their torment goes up forever and ever [aio-nas to-n aio-no-n, lit., “ages of the ages”]; and they have no rest day and night, those who worship the beast and his image, and whoever receives the mark of his name.” The double usage of the pluralized aio-nios (“ages”) is used by the author to accentuate the never-ending torment.
Revelation 20:10: “And the devil who deceived them was thrown into the lake of fire and brimstone, where the beast and the false prophet are also; and they will be tormented day and night forever and ever [eis tous aio-nas to-n aio-no-n].”The Greek phrase eis tous aio-nas to-n aio-no-n (lit., “unto the ages of the ages”) is the strongest way to express unending duration. The fact that the words are plural in number (as with 14:11) and the double use of the article (“the”) further emphasizes the concept of never-ending duration: The Greek takes its greatest term for time, the eon, pluralizes this, and then multiplies it by its own plural, even using articles [“the”] which make these eons the definite ones.” Also, as with 14:11, the phrase “day and night” is juxtaposed with “forever and ever” stressing the fact that the “torment” is perpetual, never-ending for the objects of God wrath.
To distinctly express the everlasting suffering for the unregenerate, the biblical authors used the phrase “unquenchable fire” (Matt. 3:12; Luke 3:17; and Mark 9:43). The word translated “unquenchable” is from the Greek word asbestos. According to recognized lexicons, the term carries the meaning of “unquenchable, the eternal hell fire to punish the damned” (Enhanced Strong’s Lexicon); “inextinguishable” (BDAG); “pertaining to a fire that cannot be put out” (Louw and Nida); “unquenchable, inextinguishable” (Liddell and Scott)
The evidence for the never-ending nature of hell is undeniable. Admittedly, this doctrine is difficult to discuss. However, the totality (all parts) of biblical truth must be preached. The Gospel is the proclamation of the Son’s cross-work—the very basis of our justification. The Gospel is, indeed, good news, but only because of the bad news: God’s wrath continues to remain on him who denies the Son. Hence, the Son was sent was to save His people from God’s wrath: “having now been justified by His blood, we shall be saved from wrath of God through Him” (Rom. 5:9; cf. 1 John 2:2).
God being perfect and holy does not merely wink at open defiance against His infinite majesty and holiness. It was the cross-work of the Son that provided sinners a way of escape from the divine wrath due for sin. [http://www.christiandefense.org/Articles.For.htm]
 Robertson, Word Pictures, vol. 1.
 Aio-nion is the direct object (accusative case) of the adjective aio-nios (although, there is no difference in meaning).
 R. C. H. Lenski, The Interpretation of St. John’s Revelation, 438. Also note, the same “emphatic construction” is found in Revelation 1:6; 4:9; and 5:3, where it refers to the everlasting worship of God.
 The “Gospel” is from the Greek term euaggelion (eu = “good” and angelion = “announcement”) from which we get our word evangelist/evangelism. Thus, an “evangelist” is one who proclaims the good news.
 In John 3:36, the term “abides” (NASB) is from the Greek word menei. The verb is active and in the present tense indicating that the wrath of God is a continuous reality for those who deny the Son (cf. 1 John 5:12).