Matthew Bates argues in The Birth of the Trinity that Trinitarian theology emerged from prosopological reading of the Old Testament. This isn’t the same as typology. In a typological reading, David, say, is “regarded . . . as a type or pattern for the future Christ, while at the same time, because the king embodied Israel’s national sorrows and hopes he was also a type in the sense of a corporate symbol, allowing early Christians to see an imitative correspondence between David, Israel, and the future Christ” (9).
Prosopological exegesis sees things otherwise. The primary speaker is the Logos of the Spirit, speaking through the prosopon of the human prophet. The divine agent “spoke through the human prophet in the semblance of other persons – frequently as the Father and the Son” (33).
In Romans 15:2-3, for instance, Paul quotes Psalm 68:10, attributing it to Christ: “the insults of those who were insulting you fell upon me.” In Bates’s view, “Paul reads these words as spoken in the past by David, but nonetheless as containing a real future conversation between the Father and the Son as facilitated by the Spirit that looks backward in time on the crucifixion.” Read from this angle, this passage shows that “the Son loves the Father so much that the Son, speaking via the Spirit in the past tense as if the cross is a fait accompli, tells the Father that he voluntarily bore in the passing the reviling insults by which the godless cursed the Father. . . . the Son is willing to suffer intensely here not because of his love for humanity per se, but because he loves his Father so much that he wants to should the hostile words aimed at him” (6).
More generally, prosopological readings reveal “a Father, Son, and Spirit who are characterized by relentless affection and concern for one another. . . . prosopological exegesis affirms and further develops the notion that for the earliest Christians the God of Israel had revealed himself as a personal God” (7).
Whatever the final verdict on Bates’s overall claims about the role of prosopological exegesis in the development of Trinitarian theology, his approach opens up beautiful, rich Trinitarian readings.