In his contribution to Advancing Trinitarian Theology, Stephen Holmes defends the classic notion of divine simplicity, that God’s operations ad extra are undivided. Divine actions, he argues, arise from the eternal relations of origin within the Trinity: “Son and Spirit have a movement from an origin in their eternal being, and so their sending corresponds to their eternal relation of origin” (73). So far, so Augustinian.

Holmes raises the obvious question about the coherence of Trinitarian theology with the facts of the gospel: How can we say that the Son became incarnate if God’s ad extra operations are undivided? His answer, which he admits is put “extremely crudely and schematically” is: “the single work of salvation was initiated by the Father, carried forth by the mission - and the passion - of the Son, and is being brought to perfection by the mission of the Spirit.” But this has to be seen as “one single activity, an inseparable operation. What from our perspective looks like several discrete activities is one single inseparable work in divine intention and execution, and so the particularity of the divine missions may be maintained without compromising the claim of inseparable unity” (74).

The crudeness comes from the suggestion that the Father initiates and then stops acting; the Son lives, dies, rises, and then turns things over to the Spirit to tidy up. Holmes doesn’t mean that. 

That obvious crudeness is not the only problem with the formulation. It’s not clear what precisely Holmes means. Does “one single activity” entail something like this: When the Father “did not spare His own Son but delivered Him up for us all,” Father was doing the same thing as when He “raised Jesus from the dead”? Is the Son’s “laying down My life” the same act as “taking it up again”? Assuming that the cross and resurrection are divine actions, are they the same action? 

Or: Does this mean that “descending like a dove” is identical to “speaking from heaven,” both of which are identical to “going down into the water, and coming up again”? 

Neither a simple Yes or No is helpful for Holmes. Take Yes: If they are the same action, then it seems we’ve evacuated God’s actions of any real contact with temporal history. (Call this the Jenson critique.) If God’s actions in time are not particular actions, distinguishable in some way, can they be actions in time at all? Simplicity here seems at odds with incarnation; which is to say, at odds with the gospel.

I don’t think this is what Holmes means. I suspect he means to stress that God’s saving acts are “inseparably” united. Descending as a dove is something that the Spirit does; but it’s part of a “single” act of baptizing and anointing the Son for His work. If that’s the case, it’s not clear why we can’t put things differently: Father, Son, and Spirit are inseparably united in every act of redemption, but they act distinctly according to their distinct personal characteristics. In every act, the Father always acts paternally, the Son filially, the Spirit spiritually. You can still say an act is a “single act” but you’d have to add that it’s a single complex action involving the distinguishable actions of three distinct persons, Or, better, there is a whole series of acts, each one of which is a single but complex action of Father, Son, and Spirit. Is that still consistent with simplicity as Holmes defines it? It doesn’t seem so. But if he doesn’t mean that (for God) “death” is identical to “resurrection,” then it’s not clear how he avoids this conclusion.

To put the last point more simply: Holmes can say “salvation” is a single act only because he stretches the word “salvation” to encompass a series of historical events. That’s not the most basic, or most accurate, way to talk about salvation. Nothing wrong with it, but the New Testament often summarizes the gospel in different terms, enumerating distinct moments of Jesus’ history (e.g., “delivered up for our transgressions, raised for our justification”). Holmes is forced to this broad terminology because of his commitment to simplicity.

It seems best to start from the gospel story and to affirm simplicity insofar as it is consistent with and supports the gospel. If it interferes with the gospel, then it should be revised accordingly.