Short answer. The Greek does not settle it, in either direction. English "hell" flattens three different words: Sheol, Hades, and Gehenna. The phrase behind "eternal punishment" (Matthew 25:46), kolasis aiōnios, is built on aiōn, "age", but reading it as "of the age to come" rather than "everlasting" is a real, minority position. The composite torture chamber is a construction; an end to the punishment is a wager.
Three words walked into English; one walked out
The single word "hell" is doing the work of three words the biblical writers kept apart. Sheol is the Hebrew grave, the undifferentiated underworld where everyone goes, righteous and wicked alike, a place of silence rather than fire, where the dead do nothing, plan nothing, and know nothing (Ecclesiastes 9:10), a pit where even the faithful psalmist expects to be cut off from God's remembrance (Psalm 88). Hades is the Greek underworld the translators reached for to render it. And Gehenna (the word the Gospels' Jesus actually uses for fiery judgment) is a place name: the Valley of Hinnom, a real ravine outside Jerusalem's walls (Joshua 15:8), infamous as the site where children had been burned in sacrifice (Jeremiah 7:31).
Three words, three pictures; translation fused them into one furnace. That much is bedrock. So is this: the sorted, two-destination afterlife (saved up, damned down) is a late development within the biblical tradition itself. The older Hebrew scriptures know the grave. They do not know the everlasting fire.
The aiōnios question
The proof-text is Matthew 25:46: the goats go to kolasis aiōnios, the sheep to zōē aiōnios ("eternal punishment," "eternal life." The adjective aiōnios is built on aiōn, "age") the root English keeps in eon. So a live question: does it mean "everlasting," or "belonging to the age (to come)", the quality of the coming age rather than a clock that never stops?
Here is the calibration, stated plainly. The "of the age" rendering is a real but minority reading. Ilaria Ramelli and David Konstan traced the word across the breadth of Greek literature (Terms for Eternity, 2007) and showed it genuinely carries that sense in many authors; the case is serious scholarship, not internet etymology. But the majority of scholars read zōē aiōnios as everlasting life, and the adjective as everlasting in both halves of the verse. Both facts belong on the table.
And one popular argument should be retired by both sides: the verse's symmetry. One adjective governs both nouns, so (the argument runs) if the punishment ends, so does the life; or conversely, since the life is endless, so is the punishment. The symmetry is direction-neutral. It forces the two phrases to share a sense; it does not decide whether that shared sense is "age-long" or "everlasting." It is a constraint, not a verdict.
Correction, ruin, and the book everything leans on
A second Greek argument needs the same honesty. Aristotle distinguishes kolasis (punishment inflicted for the sufferer's own good) from timōria, retribution inflicted for the punisher's satisfaction (Rhetoric 1.10). Matthew's word is kolasis, and universalists from antiquity onward have leaned on the difference: Jesus chose the corrective word. But that clean line is classical; by the Koine Greek of the New Testament it had largely eroded, and the standard lexica decline the corrective sense for Matthew 25:46. The corrective reading is something the word could carry, not what it plainly meant.
Meanwhile the strongest proof-text outside Revelation points the other way. 2 Thessalonians 1:9 threatens olethros (ruin, destruction) language closer to annihilation than to a deathless torture sustained forever. The proof-texts for unending conscious torment lean overwhelmingly on Revelation: an apocalypse written in code, and the most contested book in the canon.
The bottom line
That "hell" as one eternal torture chamber is a constructed composite (three flattened words, a late two-destination sorting, an adjective stretched over the joints) is bedrock. The corrective-universalist reading of the punishment texts, argued at full strength in David Bentley Hart's That All Shall Be Saved (2019), is coherent and serious, and it is a minority reading, held as a wager, not the plain sense recovered at last. Anyone who tells you the Greek "settles it" (toward everlasting torment or toward universal restoration) is overselling. What the Greek actually does is quieter and more interesting: it takes the certainty away from everyone.
Common questions
Does the Bible say hell lasts forever?
Not cleanly. The key phrase, kolasis aiōnios (Matthew 25:46), is built on aiōn, "age," and can be read as "everlasting" or as "belonging to the age to come." The majority of scholars read it as everlasting; a serious minority reads it as age-long. The Greek constrains the question without closing it.
What does aiōnios mean?
It is a Greek adjective built on aiōn ("age," the root behind English "eon"). It can carry "everlasting" or "of the age to come." Ilaria Ramelli and David Konstan documented the "of the age" sense across Greek literature; most scholars still render it "everlasting." Both readings are defensible, which is precisely the point.
Is hell the same as Sheol, Hades, and Gehenna?
No. English "hell" flattens three distinct words. Sheol is the Hebrew grave, where everyone goes alike. Hades is the Greek underworld the translators borrowed to render it. Gehenna is a real place, the Valley of Hinnom outside Jerusalem. One eternal furnace is a translation composite, not a single biblical word.
What is Christian universalism (apokatastasis)?
The view that punishment is corrective rather than endless, and that all are finally restored. It is ancient, argued by Origen and Gregory of Nyssa, and defended today by David Bentley Hart in That All Shall Be Saved (2019). It is coherent and serious, and it is a minority reading held as a wager, not the plain sense of the text.
This is the calibrated version of an argument the internet oversells in both directions: bedrock marked bedrock, wagers marked wagers. Where the furnace came from, who assembled it, and what the fire was before the furnace: that story is in the book.
Sources
I. Ramelli & D. Konstan, Terms for Eternity (2007); D. B. Hart, That All Shall Be Saved (2019); Aristotle, Rhetoric 1.10; Psalm 88; Ecclesiastes 9:10; Joshua 15:8; Jeremiah 7:31; Matthew 25:46; 2 Thessalonians 1:9.