Roger Olson writes,
Here is a quote from Rowan Williams: "Trinitarian theology, in so far as it is concerned with what 'kind' of God Christians worship, is far from being a luxury indulged in solely by remote and ineffectual dons; it is of cardinal importance for spirituality and liturgy, for ethics, for the whole of Christian self-understanding." (Wrestling with Angels: Conversations in Modern Theology, p. 142) This statement appears near the end of a magisterial discussion of Karl Barth's doctrine of the Trinity that is equally complimentary and critical. But I lift it out here as a stand-alone statement, independent of the context, because it expresses a kind of over-arching evaluation of the doctrine of the Trinity or “trinitarian hermeneutics." For Williams, as for Barth, as for numerous other Christian theologians past and present, the doctrine of the Trinity is crucial, essential, indispensable to a robust and healthy Christian view of God.
I quite agree.
The entire post can be read here.