The whole is worth reading. The lectures begin about page 44. This section is stimulated by the word τοῖς ἁγίοις ... καὶ πιστοῖς ἐν Χριστῷ Ἰησοῦ. Wright points out that Barth's reading is: To the saints and believers in Christ Jesus.
I was impressed as I have been before with the way Barth approaches and muses on the text. Over to you...
Holiness which is clearly visible, tangible, and perceptible (humanly speaking) is not holiness.
Nothing is holy by virtue of what it is or is not – by itself, independent of God. None of us is holy by virtue of what we believe or do not believe, do or do not do. God is the one who makes holy what will always remain unholy. And God reveals what is holy as he makes the creature holy.
Only the holy of God exists in the sphere where God himself is holy and plans to do things for them and with them that they cannot resist; any holiness springing out of human activity would be our own rather than the holiness which is uniquely and completely God’s.
Holiness is a relationship with God. This relationship is established by God. It is never simply a given. It is never something which has already happened. For the human creature, it will never be anything other than a question and goal; but as free grace, it becomes more than a question and goal. It exists wonderfully, each moment that it is established as God’s eternal election; and absolutely no law could possibly be at work, above or apart from God’s beneplacitum [“good pleasure”] diverting the course of this election.
To call a person holy means that God eternally disturbs him and fills him with joy, that he has laid his hand upon the creature. He is attacked and wounded right at the core of his life, [“an seiner vitalsten Stelle.” Literally, “where he is most vital or alive” or “the source of his energy and power.”] namely in his subjectivity, in his existence.
Existentially, he is no longer his own. He himself no longer lives. He resembles a wheel [Exzenterrad] which no longer revolves around its own center. As God first appeared to Abraham, God appears at his dwelling like a stranger, making a promise and demanding obedience.
Has a miracle occurred? No, there is no miracle. Everywhere we turn, all we can see is the creature, living in sin and death. God remains hidden – fundamentally hidden – after he has revealed himself to the creature; precisely because he has wrapped himself in the impenetrable mystery of his divinity, he has revealed himself as his God: as his God, because he is infinitely near those who are utterly lost, destitute, and lonely, whose gods and idols lie shattered before them; but he has also revealed himself his God, because unlike all gods and idols, he draws near in his infinite distance; he is majestically free with the creature while remaining utterly unapproachable. When God claims a person as his holy one, what occurs is not a miracle [Mirakel] but a wonder [Wunder], the wonder of knowing [Erkenntnis].
The full text of these notes (over 300 pages) is here