"the being of Jesus Christ, the unity of being of the living God and this living man, takes place in the event of the concrete existence of this man. It is a being, but a being in a history. The gracious God is in this history, so is reconciled man, so are both in their unity. And what takes place in this history, and therefore in the being of Jesus Christ as such, is atonement. Jesus Christ is not what He is—very God, very man, very God-man—in order as such to mean and do and accomplish something else which is atonement. But His being as God and man and God-man consists in the completed act of the reconciliation of man with God."
Karl Barth, CD IV/1, §58.3 ("Jesus Christ the Mediator"), pp. 126-127. The key to the overcoming of the old Person-and-Work dichotomy is the presence here of the emphasis on "history", "act".