Another of the central tenets of Childs’ work is that the bible is a witness. Not only this, but, as developed above, the Old Testament is also Israel’s witness; the canonical process attests to this fact. For Childs, “The goal of a new approach is to seek to do justice to the theological integrity of Israel’s witness while at the same time freely acknowledging the complexities of all human knowledge and the serious challenge of modernity to any claims of divine revelation.” But Childs never rejected efforts to read the biblical text diachronically as many of his opponents argued. He always believed that, “the crucial distinction between reading the text as witness rather than just as source does not call into question the important diachronic dimension of Israel’s history with God.” Childs’ canonical approach, then, aims to maintain scholarly rigor — which includes study of the text’s ostensive reference — as well as respect the biblical canon, reading it from within the believing community.
Additionally, Childs is explicit that the canon is also a witness to Jesus Christ. This commitment is rooted in the early church’s insistence on adopting and using the Jewish Scriptures as their own. The first generations of Christians had only these writings and were convinced that they bore witness to Christ. Childs writes,
“In a similar manner, I would argue that the Old Testament functions within Christian scripture as a witness to Jesus Christ precisely in its pre-Christian form. The task of Old Testament theology is, therefore, not to Christianize the Old Testament by identifying it with the New Testament witness, but to hear its own theological testimony to the God of Israel whom the church confesses also to worship. Although Christians confess that God who revealed himself to Israel is the God and Father of Jesus Christ, it is still necessary to hear Israel’s witness in order to understand who the Father of Jesus Christ is. The coming of Jesus does not remove the function of the divine disclosure in the old covenant.”
It is important to note here that Childs is careful not to flatten the Old Testament witness. He is keenly aware of the possibility of ignoring the distinctive witness of the Old Testament by Christianizing it and re-framing Israel’s witness contained therein. Instead, Childs is deeply concerned to get to the subject matter (res) of the text, which is Jesus Christ. Not only does the New Testament bear witness to Christ, but the early church adopted the Old Testament as Scripture because of their conviction that the res of these texts was Christ as well. Thus, the Old and New Testaments’ distinct witnesses are not identical, but not, therefore, mutually exclusive. Both testaments’ witnesses must be heard individually and collectively.
Of course, as soon as canon is construed in these terms, the attitude one adopts when approaching the text will be affected. This effect which canon has on the reader is what Childs calls the theological extension. He writes,
I also included in the term ‘canonical’ an important addition component which was a theological extension of its primary meaning. The canonical form of this literature also affects how the modem reader understands the biblical material, especially to the extent in which he or she identifies religiously with the faith community of the original tradents. The modern theological function of canon lies in its affirmation that the authoritative norm lies in the literature itself as it has been treasured, transmitted and transformed — of course in constant relation to its object to which it bears witness — and not in ‘objectively’ reconstructed stages of the process. The term canon points to the received, collected, and interpreted material of the church and thus establishes the theological context in which the tradition continues to function authoritatively for today.
Simply put, “The theological enterprise involves a construal by the modern interpreter, whose stance to the text affects its meaning.” The result of coming to terms with the Bible as canon, then, is that the Bible becomes more than a witness to the history of Israel and Israel’s religion. Far from this, when the Bible is read according to Childs’ understanding of canon, the Bible — both Old and New Testaments — bears witness to the one God who is God of both Israel and the Church; the Bible bears witness under these terms to the one God who is the father of Jesus, the lord of the Church.
 Idem, Old Testament Theology, 9.
 Idem, Old Testament Theology, 12.