Some remarks on the significance of the doctrine of the Trinity, from theologian Jürgen Moltmann:
The notion of a divine monarchy in heaven and on earth, for its part, generally provides the justification for earthly domination — religious, moral, patriarchal or political domination — and makes it hierarchy, a ‘holy rule.’ The idea of the almighty ruler of the universe everywhere requires abject servitude, because it points to complete dependency in all spheres of life.
The doctrine of the Trinity which evolves out of the surmounting of monotheism for Christ’s sake, must therefore also overcome this monarchism, which legitimates dependency, helplessness and servitude. The doctrine of the Trinity must be developed as the true theological doctrine of freedom. Religiously motivated political monotheism has always been used in order to legitimate domination, from the emperor cults of the ancient world, Byzantium and the absolute ideologies of the seventeenth century, down to the dictatorships of the twentieth. The doctrine of the Trinity which, on the contrary, is developed as a theological doctrine of freedom must for its part point towards a community of men and women without supremacy and without subjection.
— Jürgen Moltmann (tr. Margaret Kohl), The Trinity and the Kingdom (Harper & Row. German: 1980, English: 1981 ) pp.191, 192.