In his contribution to Two Views on the Doctrine of the Trinity, Stephen R. Holmes characterizes the doctrine of the Trinity as a set of hermeneutical guidelines: “What we call the ‘doctrine of the Trinity’ is, I suggest, a formal set of conceptualities developed like this: a set of conceptualities that finally allowed (or at least was believed to allow) every text to be read adequately. As such, it is not a ‘biblical doctrine’ in the sense of being the result of exegesis; rather, it is a set of things that need to be believed if we are to be able to do exegesis adequately as we hold to the truth of every text of Scripture” (35). The framework of the doctrine allows us to take every text of Scripture into account, and to avoid contradictions among them.
I’m not convinced that early Trinitarian doctrine was quite so restricted as Holmes suggests, but let’s assume he’s right in what he says about the “doctrine of the Trinity” – that it is not an ontology, but a regulation of our Scripture reading.
Even if that’s true, though, it doesn’t imply that we are necessarily minimalist in our interpretation of the biblical statements about the Trinity. It doesn’t mean that what the Scripture says about the Trinity is limited to confirming the “doctrine”; it means simply that we read what Scripture says about the Trinity in the framework of the doctrine.Thus, we can say all sorts of things about the Persons and their relations. We can say the Son can do nothing of Himself. We can say the Son sees the Father’s doings, and does them. We can say that whatever the Father does, the Son also does in like manner. We can say that the Father loves the Son. We can say that the Father shows the Son what He is doing. We can say that the Father gives the authority to judge and the power to raise the dead to the Son. We can say that the Father wants everyone to honor the Son. We can say, at base, that the Father is the Father and the Son is the Son. And all this is just from a few verses of John 5.
And we can even think about the ontological import of those statements, along the following lines: God is such that there is a Father and Son, and the Father and Son are related such that the Father loves the Son and shows the Son what He is doing. And, more distantly, we can say that the world is such that it was made by a God who is Father and Son.
These are just statements from Scripture, and by Holmes account when we say such things we must say and think them within the framework of Trinitarian doctrine. That is, the Father and Son are not related in such a way that they are of a different substance, or two gods, or that one is subordinate ontologically to the other.
In a word: The doctrine of the Trinity as Holmes defines it is not the sum total of all there is to say about the Trinity. It’s the conceptual framework within which we say many other things.