There's a famous story about a lecture that Karl Barth gave in the States, after which he was asked to sum up the findings of his career as a theologian. He paused for a moment and replied,
Jesus loves me this I know, for the Bible tells me so.
The humour and simplicity of this reply both veil and unveil Barth's absolute conviction that this is the supreme content of revelation. Theology that does not begin and end with the love of God in Christ is nothingness. Creation is an act of love. Covenant is an act of love. Incarnation is an act of love. Crucifixion is an act of love. Redemption is an act of love. Judgement is an act of love. In this story of the world we are confronted with God's love, which is a love that is not easily recognised given that it's supreme expression was a bloodied Jew dying a criminal's death on a roman cross.
I can't explain how and why that is love for me and you. And it is not a self-evident truth, no matter how easily the words "Jesus died for you" roll off our tongues. But to use a Hauerwasian turn of phrase, the work of theology is not to explain or rationalise the love of God. Rather, the work of theology is to help us see the world as unintelligible if it is not loved by the God revealed in Jesus.
The Bible that Barth read gives us a world that is the theatre of the love and the glory and the holiness of God. The preaching of the Word is a description of that world and an invitation to enter its strangeness. It is an invitation to walk by the way of grace. Christian theology has everything to do with that Way, or it profits us nothing.
Hans Urs Von Balthasar gives Barth's playful response above some scholarly frill:
Christian self-understanding (and therefore theology) can be interpreted neither in terms of a wisdom that surpasses the knowledge of the world's religions through a divine utterance (ad majorem gnosim rerum divinarum) nor in terms of man's definitive achievement of personal and social fulfillment through revelation and redemption (ad majorem hominis perfectionem et progressum generis humani), but solely in terms of the self-glorification of divine love: ad majorem Divini Amoris Gloriam.