From Joseph Ratzinger’s Introduction to Christianity (185-188)
gospel Christ says of himself:
‘The Son can do nothing of his own accord’ (5, 19 and 30). This seems to rob
the Son of all power; he has nothing of his own; precisely because he is the
Son he can only operate by virtue of
him to whom he owes his whole existence. What first becomes evident here is
that the concept ‘Son’ is a concept of relation. By calling the Lord ‘Son,’
John gives him a name that always points away from him and beyond him; he thus
employs a term that denotes essentially a relationship. He thereby puts his
whole Christology into the context of the idea of relation. Formulas like the
one just mentioned only emphasize this; they only, as it were, draw out what is
implicit in the word ‘son,’ the relativity which it contains. On the face of
it, a contradiction arises when the same Christ says of himself in St. John’s : ‘I and the
Father are one’ (10, 30). But anyone who looks more closely will see at once
that in reality the two statements are complementary. In that Jesus is called
‘Son’ and is thereby made relative to the Father, and in that Christology is
ratified as a statement of relation, the automatic result is the total
reference of Christ back to the Father. Precisely because he does not stand in himself he stands in him, constantly one with him. St. John
What this signifies, not just for Christology but for the illumination of the whole meaning of being a Christian at all, comes to light when John extends these ideas to Christians, who proceed from Christ. It then becomes apparent that he explains by Christology what the Christian’s situation really is. We find here precisely the same interplay of the two series of statements as before. Parallel to the formula ‘The Son can do nothing of his own accord,’ which illumines Christology from the son-concept as a doctrine of relativity, is the statement about those who belong to Christ, the disciples: ‘Apart from me you can do nothing’ (John 15, 5). Thus Christian existence is put with Christ into the category of relationship. And parallel to the logic which makes Christ say, ‘I and the Father are one,’ we find here the petition ‘that they may be one, even as we are one’ (17, 11 and 22). The significant difference from Christology comes to light in the fact that the unity of Christians is mentioned not in the indicative but in the form of a prayer.
“Let us now try briefly t consider the significance of the line of thought that has become visible. The Son as Son, and in so far as he is Son, does not proceed in any way from himself and so is completely one wit the Father; since he is nothing beside him, claims no special position of his own, confronts the Father with nothing belonging only to him, retains no room for his own individuality, therefore he is completely equal to the Father. The logic is compelling: iof there is nothing in which he is just he, no king of fenced-off private ground, then he coincides with the Father, is ‘one’ with him. It is precisely this totality of interplay that the word “Son” aims at expressing. To John ‘Son’ means being-from-another; thus with this word he defines the being of this man as being from another and for others, as a being that is completely open on both sides, knows no reserved area of the mere ‘I.’ When It thus becomes clear that the being of Jesus as Christ is a completely open being, a being ‘from’ and ‘towards,’ that nowhere clings to itelf and nowhere stands on its own, then it is also clear at the same time that this being is pure relation, pure unity. This fundamental statement about Christ becomes, as we have seen, at the same time the explanation of Christian existence. To John, being a Christian means being like the Son, becoming a son; that is , not standing on one’s own and in oneself, but living completely open in the ‘from’ and ‘towards.’ In so far as the Christian is a ‘Christian,’ this is true of him. And certainly such utterances will make him aware to how small an extent he is a Christian.
“It seems to me that this illuminates the ecumenical character of the passage from a quite unexpected angle. Everyone knows, it is true, that Jesus’ ‘high priestly prayer’ (john 17), of which we are speaking, is the basic charter of all efforts for the unity of the Church. But do we not often take far too superficial a view of it. Our reflectrions have shown that Christian unity is first of all unity with Christ, which becomes possible where insistence on one’s own individuality ceases and is replaced by pure, unreserved being ‘from’ and ‘for.’ From such a being with Christ, that enters completely into his openness, that would want to hold on to nothing of its own individuality, (cf. also Phil. 2, 6f), follows the complete ‘at-one-ness’ –
That they may be one, even as we are one.’ All not-at-one-ness, all division, rests on a concealed lack of real Christliness, on a retention of individuality which hinders the coalescence into unity.
“I think it is not unimportant to note how the doctrine of the Trinity here passes over into an existential statement, how the assertion that relation is at the same time pure unity becomes transparently clear to us. It is the nature of the Trinitarian personality to be pure relation and so the most absolute unity. That there is no contradiction in this is probably now evident. And one can understand from now on more clearly than before that it is not the ‘atom,’ the indivisible smallest piece of matter, that possesses the highest unity; that on the contrary, pure oneness can only occur in the spirit and embraces the relatedness of love. Thus in Christianity the profession of faith in the oneness of God is just as radical as in any other monotheistic religion; indeed, only Christianity does it reach its full stature. But it is the nature of Christian existence to receive and to live life as relatedness, and thus to enter into that unity which is the ground of all reality and sustains it. This will perhaps make it clear how the doctrine of the Trinity, when properly understood, can become the reference point of theology that anchors all other lines of Christian thought.”
Let us round off the whole discussion with a passage from St. Augustine that elucidates splendidly what we mean. It occurs in his commentary on Stl. John and hinges on the sentence in the Gospel that runs, ‘Mea doctrina non est mea’ – ‘My teaching is not mine, but his who sent me’ (7, 16). Augustine has used the paradox in this sentence to illuminate the paradoxical nature of the Christian image of God and of Christian existence. He asks himself first whether it is not a sheer contradiction, an offense against the elementary rules of logic, to say something like ‘Mine is not mine.’ But, he goes on to ask, digging deeper, what, then, is the teaching of Jesus that is simultaneously his and not his? Jesus is ‘word,’ and thus it becomes clear that his teaching is he himself. If one reads the sentence again with this insight, it then says: I am by no means just I; I am not mine at all; my I is that of another. With this we have moved on out of Christology and arrived at ourselves. The ‘I’ is simultaneously what I have completely and what least of all belongs to me. Thus here again the concept of mere substance (=what stands in itself!) is shattered, and it is made apparent how being that truly understands itself grasps at the same time that in being itself it does not belong to itself; that it only comes to itself by moving away from itself and find its way back as relatedness to its true primordial state.
Such thoughts do not make the doctrine of the Trinity unmysteriously comprehensible, but they do help, I think, to open up a new understanding of reality, of what man is and of what God is. Just when we seem to have reached the extreme limit of theory, the extreme of practicality comes into view: talking about God discloses what man is; the most paradoxical approach is at the same time the most illuminating and helpful one" (My emphasis).
P.s. In the light of the above, it is evident that the traditional scholastic metaphysic, which holds "substance" to be the prime meaning of "being," has become an obstacle in giving an account of
reality and freedom understood as "Word of God" and person.