By Jimmy Stephens:

Firstly, an appeal to mystery, by itself, does not support PSA and neither does it rule out PSA. One could appeal to mystery in favor of PSA or in favor of an alternative. Mystery is invoked wherever we run out of abductive tools independent of a doctrine we aim to support non-abductively, not as a reason in itself to believe or disbelieve a doctrine.

For example, we affirm the Trinity and the hypostatic union. We very quickly run short of metaphysical principles by which to expound these doctrines. Ultimately, we do not know how they are true, but we have non-abductive reasons in the meantime to think that they are true. Namely, the Bible teaches them.

So, our opponents have misplaced the nature and role of mystery in theology.

Secondly, whatever PSA’s mysteriousness might be, it is taught in Scripture by good and necessary deduction, as Westminster might put it. The doctrine of PSA is made no less necessary to soteriology than the doctrine of God’s triunity is to theology or Christ’s deity is to Christology.

Therefore, any good critique of PSA will have to refute absolutely the exegetical arguments made in its favor.

Thirdly, our opponents’ lazy and misguided appeal to mystery is self-refuting. If we can arbitrarily appeal to mystery whenever and however we like, that suits atheists, Hindus, and Mormons just as well. Indeed, this is just subjectivism disguising itself as mock religious humility.

The invocation of mystery must be guided by Scriptural clarity: it only occurs when we know that some important doctrine is true even though we cannot explain how. Specifically, we have no abductive tools or metaphysical principles independent of the doctrine by which to elucidate it, therefore no final abductive reasons independent of the doctrine itself, and must rely on other reasons to believe it.

Short of this episto-hermeneutic principle of mystery, our opponents tacitly endorse subjectivism.

Fourthly, an ethical problem faces alternatives to PSA. Namely, they appear to damage the equal justness and graciousness of God and to naturalize evil. Indeed, to the extent one naturalizes evil, one trivializes justice and grace; and to the extent one assuages God’s justness or grace, one naturalizes evil. This is to say that alternative atonement theories inevitably remove personal responsibility in the creature, banalize the Day of Judgment, and falsify Biblical claims about the justness or graciousness of God’s character.

This is because genuine alternatives to PSA threaten the legal, punitive, and/or perfectly consistent nature of the atonement. If the atonement is not penal substitution – Christ is not satisfying the penalty naturally due to (believing) sinners, their sin imputed to him even as his righteousness is imputed to them – then one of three elements must be cut from Scripture. God’s wrathful disposition and just character must be subtracted, or if not, the inherently legal-desserts nature of human agency and sin must be subtracted, or if not, the seriousness of sin must be subtracted. Worse case scenario, a combination of these occurs.

These all naturalize evil by making human sin morally excusable or, to some extent, by making human sin an amoral category of mistake. Sin becomes an “oopsie” due to fallibility, frailty, or because evil is just not that evil.