Where there's one will, there's no way
Cross-posted from Creed Code Cult
Thanks to Jason Stellman (JJS) for inviting me to the discussion at Creed Code Cult concerning penal substitution. To recap, we have been discussing what one might call the "strong" view of penal substitution, which says not only that Christ paid the penalty by sin but that the sins of the elect were punished by God in Christ. This imputation of guilt to Christ is sometimes referred to in Protestantism as "double imputation," a mirror image of the righteousness of Christ being imputed to sinners. When we have been talking about "penal substitution" (P-sub), we have been using the term in this strong sense.
In his paradigms series, JJS has examined the doctrine of the atonement from two perspectives: the top-down view (in which God is demanding the atonement to satisfy His wrath against sin and His need to punish sin) and the bottom-up view (in which God is reaching down to meet our need for reconciliation). By examining Biblical, historical, and philosophical records over time (the Christian "data"), we can determine which view more likely explains the existence of these records of Christian beliefs.
My criticism of the top-down view is that it cannot possibly be reconciled with the doctrine of the Trinity, specifically the doctrine that the Trinity has numerically one will. Just as the three Persons of the Trinity are not three gods but one God, so the will of the Trinity is not three wills but one will. This means that the acts of God with respect to other things are always acts of the entire Trinity; in Latin, this is stated as opera Trinitatis ad extra indivisa sunt ("the external works of the Trinity are indivisible"). The only acts of the Trinity that are distinct are (1) the internal acts of begetting the Son and spirating the Holy Spirit and (2) the acts (and suffering) of the Son according to His assumed human nature.
The reason people have trouble with this is that everybody knows (or at least thinks he knows) that the Trinity have different roles in the economy of salvation, the so-called divine missions. Specifically, the Son is sent by the Father in the Incarnation, and the Holy Spirit is sent by the Father and the Son at Pentecost. One might therefore think that the Son and the Holy Spirit must be doing different things; their actions can't possibly all be identical. But that's an unwarranted conclusion. From God's perspective, the acts are identical and common, but they manifest the presence of God to us in different ways.
Take the indwelling of the Holy Spirit: the entire Trinity is indwelling the soul, but that is experienced by us as the presence of the Holy Spirit particularly. Likewise, the entire Trinity wills the Incarnation, but the relation of the assumed human nature to the Word of God is unique; only the Son is Incarnate of the Virgin Mary. The reason this works is the harmony between the sending of the Son and the Holy Spirit in time and the eternal begetting and spiration of the Son and the Holy Spirit. Even though the sending of the Son and Spirit in time are common acts of the Trinity, we can still experience them as being individuated in some sense because they act as true signs for the eternal relations that define the Persons of the Trinity.
If we now ask what this means for our paradigm question, we come to a stark realization: the bottom-up paradigm is built into the idea of divine missions! By contrast, P-sub, the view that a divine Person was sent into the world to suffer an act of divine wrath or punishment, is absolutely incompatible with the doctrine of divine missions. First, the act of sending a Person to suffer divine wrath or punishment has no possible analogue in the eternal processions, because the Persons cannot be wrathful against each other in begetting or spirating. Second, in the alleged "mission" of P-sub, Christ would not be made present as an object of divine wrath to us, but rather as an object of divine wrath to God, which violates the fundamental concept that divine missions represent distinctions manifested to us rather than resulting from distinctions in God. Lastly, there appears to be no way that an act of divine wrath or punishment against any of the divine Persons can be one will with the others, since each other Person simultaneously and eternally wills to be sinless.
In short, if we accept the Nicene doctrine that there is only one God with only one divine will and the corollary doctrine of divine missions, we cannot accept the top-down paradigm of P-sub.