In a couple earlier posts, I’ve commented on the “intrinsicism” in Athanasius.  One additional point: Rather than seeing intrinstic/extrinsic as metaphysical opposites, Athanasius’ sees the question in a redemptive-historical, eschatological framework.  Extrinsicism is the order of the old, intrinsicism, because of the incarnation, is the order of the new.

That seems to work: Under the old, God was veiled, “incarnate” in a temple; He wrote on objectified tablets of stone.  In the new, He comes to look us in the face, incarnate in flesh, and writes on tablets of the human heart with the ink of the Spirit.

What happens to the order of sacraments in that case?  One might rush on to pietist inwardism.  That would be a mistake: The Son comes in the flesh ; intrinsicism is not an evacuation of flesh, but a transformation of flesh from the inside.  Augustine was right.  The new sacraments are fewer and simpler, also more efficacious.