New essay published in Commonweal: “The Specter of Marcionism"

I've got a new essay published in the latest issue of Commonweal titled "The Specter of Marcionism." It uses the combined examples from last year of Andy Stanley's controversial teaching on the Old Testament and the First Things review relitigating the Mortara case to think about the different ways in which Protestants and Catholics struggle with the election of the Jews, Israel's scriptures, and supersessionism. Here's a taste:

"On this, all can agree. God and the Jews are a package deal. As 1 John 2:23 says of God and Christ—that one cannot have the Father without the Son, or the Son without the Father—so here: you cannot have Abraham’s God without Abraham’s children. Reject the latter and you lose the former. In its rejection of Marcionism, the church staked a claim to this principle: the only God with whom it would have to do was the Jewish God, the God of Moses, Hannah, Mary, and Jesus. But the church’s consistency in maintaining this principle was uneven at best. The specter of Marcion continued to haunt Europe. It even casts its long shadow over the Shoah. It is no accident that history’s greatest crime against the Jews came in the heart of Christendom. No longer did Israel’s menace wear the face of a Pharaoh or a Haman. Now it was the brothers of Jesus according to the Spirit who terrorized, or turned away, the brothers of Jesus according to the flesh."

Read the whole thing here.

Blessed are the heretics

I have always attributed the line "blessed are the heretics" to Stanley Hauerwas, who in his typical fashion goes on to say (paraphrasing from memory) that without the heretics the church would not be instigated into growing ever more deeply into the truths of the faith. Indeed, a quick Google search found this quote, which I'm sure is a regularly repackaged line:

"In truth, we are never quite sure what we believe until someone gets it wrong. That is why those we call heretics are so blessed because without them we would not know what we believe."

There he goes on to discuss the Apollinarian heresy as an instance of the church establishing, through hard-win effort, a more rigorous christological grammar than it previously had.

Re-reading the Confessions the other day, though, I saw that St. Augustine says something similar. In Book VII, while discussing the "books of the Platonists" and their relationship to the faith, he writes first of his friend, then of himself:

"[Alypius's] move towards the Christian faith was slower. But later when he knew that this was the error of the Apollinarian heretics, he was glad to conform to the Catholic faith. For my part I admit it was some time later that I learnt, in relation to the words 'The Word was made flesh,' how Catholic truth is to be distinguished form the false opinion of Photinus."

He continues:

"The rejection of heretics brings into relief what your Church holds and what sound doctrine maintains. 'It was necessary for heresies to occur so that the approved may be made manifest' among the weak." (VII.xix.25)

I'm curious: Who first spoke this way about heretics in the tradition, and after Augustine, did it become a mainstay? My reading in medieval heresiology is vanishingly small. I suppose I'm interested less in the general sentiment (which I'm sure is common) and more in poetic or providential or even positive language about heretics and their heresies as occasions for growth in catholic truth.