Why doesn't God stop evil and suffering? A being who is all-powerful could prevent childhood cancer, and a being who is perfectly good would want to. He does not, so either he cannot, he will not, or he is not there.

Why people find it persuasive

This is the deepest objection to Christianity and the only one most people feel before they can state it. Epicurus posed it, Hume sharpened it, and almost everyone who asks it is asking from a hospital corridor rather than a seminar room. Any response that treats it primarily as a puzzle to be solved has already failed the person asking, and Christians who reach for a tidy explanation at a funeral do more damage than any argument could.

Important distinctions

• • Logical problem of evil (God and evil are contradictory) vs. evidential problem (evil makes God improbable).
• • Defense (showing compatibility is possible) vs. theodicy (proposing God's actual reasons).
• • Moral evil (what agents do) vs. natural evil (disease, disaster) vs. animal suffering.
• • Pastoral response to a sufferer vs. philosophical response to an argument — and knowing which is being asked for.

Christian response

• • Begin by answering the person rather than the proposition. If someone is grieving, the Christian response is presence, not a syllogism; Job's friends were right for the seven days they said nothing. Scripture itself models protest — a third of the Psalms are laments, Habakkuk accuses God of ignoring violence, and Jesus quotes Psalm 22 from the cross. A faith whose own literature includes 'how long, O Lord' cannot treat the question as impious, and saying so first is not a tactic but a substantive part of the Christian answer.
• • Then distinguish the two versions, because they require different things. The logical problem claims a strict contradiction between an omnipotent, omnibenevolent God and any evil whatever. That version is widely regarded as answered: Alvin Plantinga's free-will defense in God, Freedom, and Evil showed it is at least possible that God cannot create free creatures who always choose rightly, and possibility is all that is needed to break a claim of contradiction. J.L. Mackie, the argument's foremost defender, conceded the point. This is one of the few places in philosophy of religion where something like a settled result exists.
• • The evidential version is the serious one and deserves a real answer rather than a repackaged one. It argues that the sheer quantity and apparent pointlessness of suffering — William Rowe's fawn burning in a forest fire nobody witnesses — makes God improbable even if not impossible. Several partial responses carry weight together: a stable law-governed universe capable of supporting free agents will produce tectonic plates and pathogens as a byproduct; genuine moral agency requires the real possibility of harm; and John Hick's soul-making tradition argues that some goods, courage and compassion among them, are unobtainable in a world without adversity. None of these covers every case, and pretending otherwise is dishonest.
• • Skeptical theism adds a further move, developed by Stephen Wykstra and Michael Bergmann: the inference from 'I can see no good reason for this suffering' to 'there is no good reason' is only as strong as our confidence that we would see the reason if there were one. Given the gap between finite and omniscient perspective, that confidence is low — much as a child cannot see the reason for a painful medical procedure. This is a real logical point about the strength of the inference, though it comes with a cost noted below.
• • The distinctively Christian claim is not an explanation but a location. Christianity does not say suffering is illusory, deserved, or unimportant; it says God entered it. The central image of the faith is an instrument of torture, and the doctrine of the incarnation means the God being accused of indifference is the one who was abandoned, tortured, and killed. Jürgen Moltmann's The Crucified God works this out at length: whatever God is doing about evil, he has not exempted himself from it. Coupled with the promise of resurrection and final judgment, the claim is that evil is neither ignored nor final — which is a different kind of answer than a reason, and for many sufferers a more usable one.

Christian counterresponse

Defenders respond that the comparison requires knowing what a good God would probably do, which presumes exactly the access to divine purposes skeptical theism denies, and that the accounting must include goods invisible from within a finite lifespan if the Christian claim about resurrection is true. Many Christian philosophers, Peter van Inwagen and Eleonore Stump among them, regard the evidential problem as the strongest objection to theism and treat their own answers as partial.