Rahner says that God’s self-gift “can and must” be an “ever astounding wonder, the unexpected, the unexacted gift.” In an extended footnote, he explains that this “can and must” means both that God’s self-communication is in fact unexacted, and that it must be of necessity . On the latter point: “there is no essence of a creaturely kind which God could constitute for which this communication could be the normal, matter-of-course perfection to which it was compellingly disposed.”

To which one is tempted to answer, why not? I suspect Rahner’s answer would follow along a couple of lines.

First, because “supernatural” means something like “natural to divine life.” He goes on to explain in the footnote that “grace and glory are simply speaking supernatural,” and draws out the implication that “this grace is only then conceived of in its true essence when it is recognize to be not just the created ‘accidental’ reality produced by God’s efficient causality ‘in’ a (natural) substance, but include ‘uncreated grace’ in its own concept in such a way that this may not be conceived of purely as a consequence of created grace.” He finds it “difficult to see how a purely created, accidental reality could be supernatural simpliciter .” If this is what “supernatural” means, then Rahner thinks it is clearly impossible for this to be the “normal, matter-of-course perfection” for any created nature. That would be to say that the creature’s “normal” trajectory is toward the divine.

If this is Rahner’s point, then it raises some questions about the character of the supernatural end. Rahner assumes a Creator-creature distinction, so he’s not talking about creatures becoming ontologically divine. But there’s ambiguity about precisely what divinization does mean. It appears to mean, for Rahner, some creaturely share in divine nature - a share that leaves the creature a creature, yet somehow seems to be elevating the creature above his creatureliness. Is that what 2 Peter 1 means by sharing in divine nature?

Second, more disturbingly, Rahner’s comment about the impossibility of God creating a being whose “normal” perfection is to receive God’s self-communication hints at some kind of resistance from creation itself. Creation has only so much (or no) capacity to receive God’s self-communicating love, and so it must be elevated to receive the perfection of this self-communication. But this appears to assume that creation has its own boundaries, boundaries not set by the Creator but boundaries set by the mere fact that creation is created. But that, in turn, appears to assume that creation has some degree of autonomy.