Here’s a neat quote from Barth on how the Old and New Testaments relate:
As regards handling of Old Testament texts, we maintain that for us the Old Testament is valid only in relation to the New. If the church as declared itself to be the lawful successor of the synagogue, this means that the Old Testament is witness to Christ, before Christ but not without Christ. Each sentence in the Old Testament must be seen in this context. Historical exegesis can and must be done, but at the same time we have to ask whether this exegesis does justice to the context in which the Old and New Testaments stand. Even in a sermon on Judges 6:3 it is possible both insist on the literal sense and also to set one’s sights on Christ. As a wholly Jewish book, the Old Testament is a pointer to Christ. As regards the justification of allegory, we have again to refer to the relation between the Old Testament and the New. In the Old Testament the natural sense is the issue. Preaching must bring out what the Old Testament passage actually says, but in a way that affirms the basic premise on which the church adopted the Old Testament. This does not mean that we will give the passage a second sense — just as we are not to oppose historical and Christian exposition to one another. Instead, we will see that this passage in its immanence points beyond itself. It is a signpost that gives us direction. The Old Testament points forwards, the New Testament points backward, and both point to Christ.
- Karl Barth, Homiletics Translated by Geoffrey W. Bromiley and Donald E. Daniels (Louisville, KY: WJK, 1991) 80-81.
