Often the response to Barth’s claim that natural theology is anti-Christ is that Holy Scripture refutes Barth’s claim. People will claim that the Bible itself endorses a natural theology; I have heard this rejoinder a million times myself. And if I have heard it, you can be sure Barth heard it as well; more than myself, I’m sure. In fact, because he heard this retort so often, he offers response to it in CD II/1 §26. He gives a very full and developed response to this objection towards his position, and one that I think (of course) is spot on. I have just received some responses from Wayne and Anthony to my last two posts, both from their own orientation, and with respectful tone, have pushed back against Barth’s anti-natural theological mode by appealing to some of the classic texts used to do that (i.e. Ps 19; Rom 1 etc.). It isn’t that such push-back isn’t warranted at some level. I can see how these texts and others might sound like an endorsement for some sort of natural theology, or classical ‘two-books’ theory of revelation. But I think if we think with deeper penetration, appeal to these texts themselves only reveals (pun intended) that Scripture itself has an ontology (as John Webster might say). In other words, if we have a proper doctrine of Scripture, we will understand that Scripture itself is an aspect of a grander theology of the Word; a theology of the Word that is grounded in the eternal Logos of God who is known as Jesus Christ (cf. Jn 1.1). David Fergusson has written: “The world was made so that Christ might be born,” and it is with this orientation, this doctrine of creation, this protological consideration, I suggest we ought to think the Word of God, and a doctrine of Scripture as the special aspect of God Self-revealed in Prophetic and Apostolic intonation. What I am trying to say is that Scripture, and appealing to it as a proof for the reality of natural theology is unwarranted, since Scripture itself is a species of the scandalous and particularist Self-revelation of God from the canon of God’s eternal choice to be us that we might be him by the adoption of grace in union with Christ. It is in this union that knowledge of God comes, and whereby Scripture is illumined with God’s Light wherein we come to see His light (cf. Ps 36.9). The primary point is that there is no independent revelation of God apart from what God has given particularly in His Word in Christ. There is no cosmic remainder that ‘stands behind the back of Jesus’ (cf. TF Torrance and Barth for this language). Barth says all these things more eloquently this way:
The representatives of a “Christian” natural theology, may, for example, lay great stress on the 19th Psalm, interpreted in their sense. But even so they cannot deny that if we take the Gospel of the Psalter as such and as a whole (as indeed the second half of the 19th Psalm shows, thought this is usually forgotten or dismissed on literary critical grounds), its starting point is the declaration of the glory of God by the Exodus, by the election of the patriarchs, by the sending of Moses, Joshua and the Judges, by the founding and upholding of the royal house of David, and not directly, at any rate, by “the heavens”; even allowing that it does undoubtedly say here: “The heavens declare the glory of God.” Or again, they may emphasise strongly, for example, Rom. 1.19f. and 2.12f. (likewise interpreted in their sense). But even so they cannot deny that no matter what Paul says in these places and no matter what their meaning may be, he certainly did not intend the Gospel of his Roman Epistle to be gathered from what the heathen too can know about God. On the contrary, he grounded it exclusively on what the first chapter of this Epistle calls God’s ἀποκάλυψις. Therefore, the fact that the leading and decisive strand in the biblical Gospel goes back to the knowability of God in His revelation, and not to a knowability of God existing for man in the cosmos as such, does not need to be argued here. The rationalistic interpretation of the Bible at the end of the 18th century transposed even those statements about a special revelation which belong to the main biblical strand into statements about a general revelation of God in nature, history and human reason. But (at least for the time being) this has long since been abandoned even in those quarters where the full implications of this distinction are not understood. Among thoughtful exegetes there can be no question that at its heart and decisively the Bible intends to speak from no other source than a particular revelation of God as distinct from a general revealedness—or from revelation itself as distinct from the knowledge of man in the cosmos as such.
It is hard for me to see how this can be argued with. If we are thinking consistently as Christians we will confess that we have no knowledge of God without knowledge of God as our personal Lord and Savior (cf. I Cor. 12.3). That is, as Christians, we are confessionally rooted in the reality that we have come to a knowledge of God because we have simultaneously by the Spirit, come to know God as Lord. We had no possible way of having a genuine knowledge of God prior to this reality encountering, confronting and contradicting all of our heathen notions about ‘God’ and ourselves. If this is the case, it is not clear to me how the Christian can argue for and from an abstract creation (which of course includes the whole cosmic order) wherein a background knowledge of God is ostensibly available for anyone curious enough to look into such things. This is not what the Gospel proclaims; in fact the Gospel proclaims just the opposite. The Gospel preaches that we were dead in our trespasses and sins and at enmity with the living and true God (cf. Eph 2.11f.). The Gospel proclaims that we were once dead, and in enslavement to idols: “For they themselves report about us what kind of a reception we had with you, and how you turned to God from idols to serve a living and true God, and to wait for His Son from heaven, whom He raised from the dead, that is Jesus, who rescues us from the wrath to come” (I Thess. 1.9-10). If there is no cosmic remainder behind the back of Jesus, then it is hard to understand how the Christian could ever offer a coherent argument for a natural or speculative theology of any kind.
 David Fergusson, Chapter 4: Creation, 76-7 in The Oxford Handbook of Systematic Theology, edited by John Webster, Kathryn Tanner, and Iain Torrance.
 See Irenaeus, “Preface,” in Against Heresies, book 5, where he writes: “The Word of God, our Lord Jesus Christ, who did, through His transcendent love, become what we are, that He might bring us to be even what He is Himself.”
 Barth, CD II/1 §26, (T&T Clark Study Edition), 99.