Either Allah’s mercy is finite (contradicting His attributes), or eternal punishment is excessive (challenging His justice). He can’t both apply his mercy and his justice at the same time.
Islam claims:
The tension:
Either Allah’s mercy is not actually infinite and all-encompassing, or eternal punishment is disproportionate and unjust.
You don’t get both infinite mercy and eternal retribution on finite creatures without contradiction.
“Your Lord has prescribed mercy for Himself” — Surah 6:12, 6:54
“Say, ‘O My servants who have transgressed against themselves, do not despair of the mercy of Allah. Indeed, Allah forgives all sins…’” — Surah 39:53
Constant titles: ar-Raḥmān, ar-Raḥīm, invoked in almost every surah.
“We will set up the scales of justice for the Day of Resurrection…” — Surah 21:47
“They will wish to get out of the Fire, but they will never get out of it; and for them is a lasting punishment.” — Surah 5:37
“They will abide therein forever” language appears repeatedly for the dwellers of Hell: e.g., Surah 2:162;, 4:169; 72:23.
“To Allah belongs the dominion of the heavens and the earth. He forgives whom He wills and punishes whom He wills.” — Surah 48:14
“Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills.” — Surah 4:48;, 4:116
So:
Allah can forgive, can show mercy, and chooses in many cases not to—ever.
Define:
Justice: (retributive): giving each person exactly what they deserve.
Mercy: not giving the full punishment they deserve, or giving better than they deserve.
Now the argument:
P1. If Allah is perfectly just, He must give every person exactly what they deserve—no more, no less.
P2. If Allah is perfectly merciful, His mercy is not merely partial or finite, but ultimately triumphs over judgment, or at least prevents disproportionate, maximal punishment for finite creatures.
P3. The Qur’an teaches that many people will suffer eternal, irreversible punishment in Hell (33:64–65; 5:37; 4:169).
P4. Any sin committed by a finite creature in finite time is, by nature, a finite offense; eternal, never-ending punishment is disproportionate to finite offenses.
P5. Disproportionate punishment is unjust by any coherent moral standard.
C1. Therefore, if eternal punishment is real, Allah’s justice is compromised (contrary to 4:40; 21:47), or His mercy is severely limited (contrary to 7:156; 6:12; 39:53).
Either Allah’s mercy is not truly all-encompassing and ultimate (so the Qur’an’s claims about His mercy are false), or eternal Hell makes His justice morally indefensible. Either way, the Islamic picture of Allah is internally incoherent.
The Logical Tension Between Justice and Mercy (Same Person, Same Sin)
For a given person and their sins, Allah has only two logically consistent options:
“He fully gives what they deserve” and “He does not fully give what they deserve.”
That’s a straight contradiction.
So when Muslims say “Allah is both just and merciful,” they are either:
But the Qur’an presents Allah as perfectly just and perfectly merciful in an absolute sense—and as the one who imposes eternal Hell on billions.
That’s the problem.
Assume:
Then:
So on this horn:
Allah’s mercy is not truly infinite or all-encompassing; it’s highly restricted.
The Qur’an’s rhetoric about His mercy becomes exaggerated at best, false at worst.
So either:
Either way, the advertised attributes don’t match the system.
Assume:
Then:
But the Qur’an repeatedly states that the inhabitants of Hell “abide therein forever”, and they “will never get out of it” (5:37; 2:162; 33:64–65; 4:169; 72:23).
If mercy ultimately “wins,” eternal Hell cannot remain infinite and irreversible.
If eternal Hell remains as described, mercy does not fully triumph and does not encompass all things—those people remain outside its ultimate effect.
So on this horn:
To keep mercy truly all-encompassing, you must deny or radically reinterpret the straightforward Qur’anic teaching on eternal Hell.
Then the Qur’an’s clear eschatology is wrong or misleading → Qur’an not reliable.
P1. Perfect justice means giving precisely what is deserved.
P2. Perfect mercy, if real and central, means not fully giving what is deserved in punishment, at least in many cases.
P3. For the same person and the same sin, Allah cannot both fully give them what they deserve and simultaneously refrain from fully giving them what they deserve.
P4. Islam claims Allah is perfectly just and perfectly merciful toward His creation, while also teaching eternal, unending punishment for many (33:64–65; 5:37; 4:169).
C. Therefore, Islam’s portrayal of Allah’s justice and mercy is internally incoherent: either His mercy is not truly all-encompassing, or His justice is not morally defensible, or the descriptions of eternal Hell are false.