Kaffara

The structure of a kaffara is more revealing than any single instance of it, so it is worth reading the oath case closely, since it is the one the Quran sets out at fullest length.

A person who binds themselves by an oath and then breaks it owes an expiation, and the expiation is stated as a set of options rather than a single requirement. Feed ten poor persons at the average of what you feed your own family, or clothe them, or free a slave. Whoever does not find the means for any of these fasts for three days. The closing note is that this is the expiation for oaths that have been sworn, and that oaths should be kept.

Three features of that structure carry through the other cases.

The first is that the standard of the feeding is set by the offender's own household. It is not a fixed sum, so the same fault costs more from a wealthy person than from a poor one, and the law does not have to be amended as prices change.

The second is that the fast is the fallback rather than the norm. Where means exist the expiation is directed outward, at people who need food or clothing, and only where means fail does it become a private act of self-denial. The other Quranic cases follow this pattern, and in the case of zihar the sequence runs from manumission to a fast of two consecutive months to the feeding of sixty poor persons.

The third is that a kaffara is owed and is not a devotion. It can be neglected, and neglecting it leaves an outstanding obligation. This is why the jurists treat kaffara alongside debts and vows rather than alongside prayer, and why the technical questions it raises are questions of law: whether the feeding may be discharged in money, what counts as consecutive in a two-month fast, and what a person does when an option named in the text is no longer available.

Comparative writing reaches for kaffara whenever it needs an Islamic entry under atonement, and the reach is usually too quick. The two do overlap, at the point where both mean expiation, and they diverge everywhere else. Setting out the divergence is more useful than smoothing it.

Islamic teaching holds that God forgives directly. A person who repents, makes restitution where a human being has been wronged, and resolves not to return to the fault has done what is required, and no mediator stands between the repentance and the forgiveness. Kaffara sits inside that arrangement as a specific liability attached to specific faults, not as the mechanism by which anyone is reconciled to God.

The Quran also denies, repeatedly and in nearly the same words in several places, that one bearer of burdens can bear the burden of another. That statement is not aimed at Christianity in particular but it rules out the transfer on which several of the Christian accounts depend, and Muslim writers in dialogue with Christian theology have consistently identified it as the point of divergence rather than any detail of the crucifixion narrative. The Quran also does not accept that the crucifixion happened as Christians relate it, which is a separate matter and a well known one, but the deeper difference would remain even if it did.

So the honest comparison runs like this. Both traditions have expiation, meaning a prescribed act that deals with a fault. Only one of them has an atonement in the sense the Christian doctrine gives that word, meaning a single event by which the standing of humanity before God is altered. The atlas records kaffara as what it is in its own tradition and does not enter it as the Islamic answer to a Christian question, because it is not an answer to that question and the question is not asked in this form.