The quest of Historical Jesus has been criticized through many angles, but it is interesting to see how Barth criticized this project, along with other images of Jesus: “The ‘fairest Lord Jesus’ of mysticism, the ‘Saviour’ of Pietism, Jesus the teacher of wisdom and friend of man in the Enlightenment, Jesus the quintessence of enhanced humanity in Schleiermacher, Jesus the embodiment of the idea of religion in Hegel and his school, Jesus a religious personality according to Carlyle’s picture in the theology of the end of the 19th century–all this looks at least very dubiously like a profane and sacrilegious intrusion in the Old Testament sense in which it is though possible to come to terms, as it were, with the presence of God in Christ and to take control of it with the help of certain conceptions deriving from the humanity.” (I/1, 323) Barth is against this “secularisation of God and therefore in an empowering of man”, since here “‘God’ does not remain free at all but at best must become a partner and at worst a tool of the religious man.” (324)
To put it in other words, God is a mystery because he has revealed himself in Jesus Christ. He is a mystery because he is with us. Again, the undergirding concern of Barth is the freedom of God, and this is perhaps one of the ways along which we could read Barth rightly. Indeed, Barth might even endorse this. G. C. Berkouwer, a Dutch Reformed theologian, wrote a book entitled The Triumph of Grace in the Theology of Karl Barth (1956), and Barth largely appreciated this critique by Berkouwer (IV/3, 173-180), although he added that he preferred the characterization of his theology to be “Jesus is Victor”, as Barth is concerned that the abstraction of grace might indicate a victory of a mere principle rather than a Person: “In this context, therefore, ‘Jesus is Victor’ is better than ‘The Triumph of Grace.'” (173).