We began by wondering what it might mean to speak of the immanent and economic threefoldness of God. Rahner's axiom provided leverage on the problem by showing that trinitarian theology is meant above all to be a truth about the mystery of salvation. That is, it is a way of both narrating and conceiving the God who saves and the God who saves.
The correspondence between these two emphases presented a hermeneutical problem at two methodological levels, and so the second step was to examine the meaning of the copula in Rahner's axiom in order to decide how we might (a) link up our narrative of God's history with us with God's inner history, and, having answered that, how we might (b) link up our speculation about God's ‘inner’ life with the divine reality. We replied in the case of (a) that the axiom legislates speaking of God by drafting an equivalence between the temporal history of God-with-us and the eternal history of God, and vice versa: the economic trinity is the immanent trinity, and vice versa. In the case of (b) and building on the answer to (a), we proposed an understanding of the trinity as a theological model. The model (trinity of relations) is related to the ‘modeled’ (God-in-relation) both heuristically and ontologically. The theological model of trinity therefore must incorporate imagistic as well as discursive, indirect as well as direct modes of discourse.
Finally, we indicated some of the theological and methodological consequences of understanding God as being the ‘God for us’, and of re-conceiving the doctrine of the trinity to be a theological model of salvation.