Many of us live on streets where nearly all the world’s major religions and different types of secularism and atheism are represented. We personally encounter religious viewpoints today that fifty years ago we had only read about in books. We are encouraged by the exponents of pluralism and relativism to ignore the differences and just get along. And from a personal and political vantage point this may be a good strategy. But what is true for individuals and politicians is not true for religions and philosophies. They make conflicting truth claims. From a logical point of view they may all be wrong, but they cannot all be right. I am comfortable and experienced in arguing for the truth of Christianity against atheism or for the truth of an important theological truth against a Christian thinker who denies it. But like many of you I am not all that experienced at defending the faith in discussions with Muslims, Buddhists, Hindus and others. And as I hinted above, our culture discourages us from anything but affirming encounters with representatives of other religions. I think, however, that Christians need to go beyond tolerance and politeness, and learn how to explain and defend our faith to our non-Christian neighbors. Let’s think today about how to respond to one particular non-Christian critique of Christianity.

Critics of Christianity attack at different points. Where they attack depends on what they assert as the alternative truth. Atheists object to the very idea of God, and offer nature or matter as a god-substitute. Non-Christian monotheist religions object to the status and role Jesus Christ occupies in the Christian faith and assert some other revelation or mediator or law as a Christ-substitute. Non-Christian polytheist religions find it easy to assimilate Christ as one appearance of god among many. Today I want to address certain objections to the Christian doctrine of the Trinity. I am not concerned in this essay with those Christians who object on biblical grounds to the specific doctrine asserted in the Nicene Creed. I am thinking of rational critiques by Jewish, Islamic, Theist or Deist thinkers.

These critics assume that defeating the doctrine of the Trinity defeats Christianity as a whole. And to accomplish this goal they make use of a common (and mistaken) notion that gives their objections underserved force, that is, that the simple unity of the divine being is a clear, rational truth whereas the triunity of the divine being is irrational or mysteriously beyond reason. But as a matter of historical fact, biblical Israel’s belief in the unity of the divine being was based on historical revelation and divine action, not on reasoning from nature. The best reasoning from nature at that time concluded that the divine nature was plural, that there were many gods, some more, some less divine. There are many forces and spheres within nature, and for the ancients these different forces possessed no obvious connection. And even if you examine the writings of the Greek philosophers from Plato to Plotinus, you never find a rationally plausible system that gets beyond dualism, that is, the assertion of at least two ultimate principles; and the divine realm always includes multiple levels. The history of philosophy proves that we cannot reason conclusively from the many things of our experience to a single, simple explanation for everything, much less to a single personal God. To think at all is to relate one thing to another. If there is only one thing, we are beyond thought. Hence simple monotheism is not a clear, rational truth self-evidently superior to belief in a differentiated divine unity. That there is only one, personal God is a truth that can be known only by revelation. I think it can be rationally held once believed, but just because it can be rationally held doesn’t mean it can be rationally proved. And I’ve not even addressed the question of the identity of that one God, which, of course, can be known only through the self-revelation of God, who alone, knows who he is.

If we remove the presupposition of the rational superiority of simple monotheism, the rationalist critique of the doctrine of the Trinity collapses. The question of whether God’s inner nature is absolutely without distinction or contains internal relations is beyond rational discovery. Now we can see clearly that the more basic question at issue is, has God revealed himself in such a way that calls for thinking of God as triune? Just as Jews assert that the God who called, guided, punished and saved Israel proved himself to be the one Creator of all things, Christians assert that this same God showed himself by what he did in and through Jesus Christ and the outpouring of the Holy Spirit to be eternally Father, Son and Spirit. The real question is not whether or not this assertion is as clear to reason as is the assertion of simple monotheism. Neither one is a truth discovered by or transparent to reason. The real question is whether or not God really has revealed himself in Jesus Christ and through the Holy Spirit in the way the New Testament declares. Judaism, Islam and Deism deny this; and this denial is the root of their objection to the Trinity and to Christianity as such. The rationalist objection is a distraction.