The key to understanding this is the meaning of "work:" only persons work because only persons are subjects, and work is the self-gift of a subject. Everything else "functions."
Joseph Ratzinger :
“The topic of the suffering God has become almost fashionable today, not without reason, as a result of the abandonment of a theology which was one-sidedly rationalist and as a result of the rejection of a portrait of Jesus and a concept of God which had been emasculated, where the love of God had degenerated into the cheap platitude of a God who was merely kind, and hence `harmless.’ Against such a backdrop Christianity is diminished to the level of philanthropic world improvement, and Eucharist becomes a brotherly meal. The theme of the suffering God can only stay sound if it is anchored in love for God and in prayerful attention to his love. The encyclical Haurietis aquas sees the passions of Jesus, which are summed up and set forth in the Heart, as the basis, as the reason why, the human heart, i.e., the capacity for feeling, the emotional side of love, must be drawn into man’s relationship with God. Incarnational spirituality must be a spirituality of the passions, a spirituality of `heart to heart;’ in that way, precisely, it is an Easter spirituality, for the mystery of Easter, the mystery of suffering, is of its very nature a mystery of the heart.
“Developments since the Council have confirmed this view on the part of the encyclical. Theology today is certainly no longer confronted with a Stoic ethos of apatheia, but is faced with a technological rationalism which pushes man’s emotional side to the irrational periphery and allots a merely instrumental role to the body. Accordingly, the emotions are placed under a kind of taboo in spirituality, only to be followed by a wave of emotionalism which is, however, largely chaotic and incapable of commitment. We could say that the taboo on pathos renders it pathological, whereas the real issue is how to integrate it into the totality of human existence, the totality of our life as we stand before God. (…)
“All this shows that Christian spirituality involves the senses, which are structured by and united in the heart, and the emotions, which are focused on the heart. We have shown that this kind of heart-centered spirituality corresponds to the picture of the Christian God who has a heart.”
The ontological grounding of this is the following from Benedict: “It is common enough for the theological textbooks to pay scant attention of the theological development which followed
. In many ways
one is left with the impression that dogmatic Christology comes to a stop with
a certain parallelism of the two natures in Christ. It was this same
impression that led to the divisions in the wake of Chalcedon. In fact,
however, the affirmation of the true humanity and the true divinity in Christ
can only retain its meaning if the mode of the unity of both is clarified. The
Council defined this unity by speaking of the `one Person’ in Christ, but it
was a formula which remained to be explored in its implications. For the unity
of divinity and humanity in Christ which brings `salvation’ to man is not a
juxtaposition but a mutual indwelling. Only in this way can there be that
genuine `becoming like God,’ without which there is no liberation and no
freedom (underline mine). Chalcedon
“It was to this question, after two centuries of dramatic struggles which also, in many ways, bore the mark of imperial politics, that the Third Council of
(680-681) addressed itself. On the one hand, it teaches that the unity of God
and man in Christ involves no amputation or reduction in any way of human
nature. In conojoining himself to man, his creature, God does not violate or
diminish him; in doing so, he brings him for the first time to his real
fullness. On the other hand (and this is no less important), it abolishes all
dualism or parallelism of the two natures, such as had always seemed necessary
in order to safeguard Jesus’ human freedom. In such attempts it had been
forgotten that when the human will is taken up into the will of God, freedom is
not destroyed; indeed, only then does genuine freedom come into its own.”
The key to understanding this is to go to the Scripture that says, “I have come down from heaven, not opt do my own will, but the will of him who sent me” (Jn. 6, 38). Benedict says, and I repeat: “Here it is the divine Logos who is speaking, and he speaks of the human will of the man Jesus as his will, the will of the Logos. With this exegesis of John 6, 38 the Council indicates the unity of the subject in Christ. There are not two `I’s in him but only one. The Logos speaks in the I-form of the human will and mind of Jesus; it has become his I, has become adopted in to his I, because the human will is completely one with the will of the Logos. United with the latter it has become a pure Yes to the Father’s will.”
These remarks are incalculably important because they save us from a reductionism of the human will to be an objectivized “part” of the divine Person that is not the divine Person willing, but that somehow or other wills independently as a will. In this way, it is “parallel” to the divine but not divinized and yet autonomous.
Once you do that, you will now tend to say, as does Weinandy, that the human will - and humanity of Christ in general - will suffer, but not the divine Person. In this regard, perhaps Bernard Lonergan can be helpful:
“Q. Who suffered under Pontius Pilate?
A. Jesus Christ, his only son, our Lord.
Q. Did he himself suffer, or was it somebody else, or was it nobody?
A He himself suffered.
Q. Did he suffer unconsciously?
A. No, he suffered consciously. To suffer unconsciously Is not to suffer at all. Surgical operations cause no pain, when the patient is made unconscious by an anesthetic.
Q. What does it mean to say that he suffered consciously?
A. It means that he himself really and truly suffered. He was the one whose soul was sorrowful unto death. He was the one who felt the cutting, pounding scourge. He was the one who endured for three hours the agony of the crucified.
Q. Do you mean that his soul was sorrowful but he himself was not sorrowful” [Weinandy]
A. That does not make sense. The Apostles’ Creed says explicitly that Jesus Christ, his only Son, our Lord, suffered under Pontius Pilate.
Q. Do you mean that his body was scourged and crucified but he himself felt nothing?
A. No, he felt all of it. Were our bodies scourged and crucified, we would feel it. His was scourged and crucified. He felt it.
Q. Is not Jesus Christ God?
A. He is.
Q. Do you mean that God suffered?
A. In Jesus Christ there is one person with two natures. I do not mean that the one person suffered in his divine nature. I do mean that the one person suffered in his human nature.
Q. It was really that divine person that suffered though not in his divine nature?
A. It was. He suffered. It was not somebody else that suffered. It as not nobody that suffered;”
The thrust of Lonergan’s dialogue is to point out the confusion – the reification of faculties into personal agents – objects (faculties) into subjects (persons). Only persons – or subjects – suffer since only subjects exist and are the agents or patients of action.