If any doctrine makes Christianity Christian, then surely it is the doctrine of the Trinity. The three great ecumenical creeds—the Apostles’ Creed, the Nicene Creed, and the Athanasian Creed—are all structured around our three in one God, underlying the essential importance of Trinitarian theology. Augustine once commented about the Trinity that “in no other subject is error more dangerous, or inquiry more laborious, or the discovery of truth more profitable.” More recently, Sinclair Ferguson has reflected on “the rather obvious thought that when his disciples were about to have the world collapse in on them, our Lord spent so much time in the Upper Room speaking to them about the mystery of the Trinity. If anything could underline the necessity of Trinitarianism for practical Christianity, that must surely be it!”
Yet, when it comes to the doctrine of the Trinity, most Christians are poor in their understanding, poorer in their articulation, and poorest of all in seeing any way in which the doctrine matters in real life. One theologian said, tongue in cheek, “The trinity is a matter of five notions or properties, four relations, three persons, two processions, one substance or nature, and no understanding.” All the talk of essence and persons and co-this and co-that seem like theological gobbledy-gook reserved for philosophers and scholars-maybe for thinky bookish types, but certainly not for moms and mechanics and middle-class college students.
So in a few hundred words let me try to explain what the doctrine of the Trinity means, where it is found in the Bible, and why it matters....Read the whole thing at the link.