Barth is just finishing up a really strong critique of nominalism, and the two powers of God theology (potentia absoluta/ordinata) of late medievalism. I will not detail what nominalism entails in regard to its theory on God’s two powers, other than to say that it presents a real rupture between who God might be in His inner life (in se) and who He is seen to be in His outer life (ad extra) in the economy of salvation history. It is this type of thinking that brings Thomas Torrance to assert: ‘There is no God behind the back of Jesus.’ Barth writes:

God and God alone has real power, all the real power. This is the statement of the Christian knowledge of God. The alternative that all the real power that we encounter (what we think real) is God’s power is the statement of a blind deification of nature or history or fate, and finally of man himself. The identification of God’s omnipotence with His actual omnicausality drives us to this deification, which is more or less concealed in it. That is why it is to be rejected. Certainly all true reality is based on God’s omnipotence as the only true possibility. But what this true reality is, and therefore what may and must be the occasion and object for our glorification of the divine omnipotence. If we do not know this distinction and therefore the omnipotence proper to God, we have no protection against the temptation which constantly threatens to bestow our praise of God’s omnipotence, and the awe and trust which we owe it, on one or other of the powers of falsehood and apostasy which are to be understood only as impossibilities, as powers of impotence; or on the epitome of all such impossibilities, the power of the devil.[1]

We see Barth’s themes of reprobation, and anti-natural theology most evidently in what he writes contra the nominalst god. In agreement with Barth Jesus says to both Philip and Thomas, respectively:

If you had known me, you would have known my Father also. From now on you do know him and have seen him.” Philip said to him, “Lord, show us the Father, and it is enough for us.” Jesus said to him, “Have I been with you so long, and you still do not know me, Philip? Whoever has seen me has seen the Father. How can you say, ‘Show us the Father’? Do you not believe that I am in the Father and the Father is in me? The words that I say to you I do not speak on my own authority, but the Father who dwells in me does his works. Believe me that I am in the Father and the Father is in me, or else believe on account of the works themselves. –John 14:7-11

In other words, we shouldn’t make a distinction between God’s inner/outer life, other than recognizing that the former is antecedent to the latter; that when we see the Son enfleshed, we see the whole triune God on display in His person and works. This is what Barth is ultimately saying, albeit while interacting with a foreign philosophy that has been imposed upon the Christian God. And yet what Barth is responding to in his day, still remains just as pernicious of a reality today. Reformed theologians, along with some Lutherans and others, are attempting to retrieve nominalist and then realist Aristotelian conceptions of God that present us with a God who has this sort of rupture between His inner and outer life. Thus, when we attempt to think God in these ways, the ways that Barth and Jesus rightly rebuke, we think God from our own speculative determinations about who God must be; we separate His works from His person, and then attempt to synthesize those with the power of our own wits. Quite tragic.

[1] Karl Barth, Church Dogmatics II/1 §31: Study Edition Vol 9 (London/New York: T&T Clark, 2010), 96.