The Trinity – God, although one, nevertheless exists in three persons, God the Father, God the Son and God the Holy Spirit. The word Trinity is not in the Bible. It comes from the Latin word trinitas, which means “threeness.” But even though the word is not in the Bible, the trinitarian idea is there, and it is most important. It is important because there can be no real blessing either upon ourselves or our work if we neglect any one of the persons of the Godhead.
In the minds of some, the difficulty of understanding how God can be both one and three is reason enough to reject the doctrine outright. Such people cannot understand the Trinity and therefore deny it. Often they complain that theology should be “simple,” because simplicity is beautiful, God is beautiful and must therefore be simple and so on. But this is a misunderstanding of reality as well as of the nature of the God revealed to us in the Bible.
Why should reality be simple? Actually, as C. S. Lewis has pointed out in Mere Christianity, it is usually the case that reality is odd. “It is not neat, not obvious, not what you expect.… Reality, in fact, is usually something you would not have guessed.” This is true for very common things — a table and chair, for example. They seem simple, but if we are to speak of their construction from atoms and of the forces that hold these atoms together, even these supposedly “simple” things go beyond our minds’ comprehension. More complex things are even more beyond us. Thus, the maker of the table and chair is more complicated than the things he has made, and God, who made the maker, should be the most complicated and incomprehensible of all.
God has revealed some of his complexity to us in the doctrine of the Trinity. What we know about the Trinity we know only because of God’s revelation of it in the Bible.
The first thing we must say is that Christians believe, just as much as Jews believe, that God is one. Because Christians also believe in the Trinity they have been inaccurately accused of believing in three gods, “tritheism,” a form of polytheism. It is true that Christians see a plurality within the Godhead, because God himself reveals that it is there. Christians, like believing Jews, are monotheists. That is, we believe in one God. We will recite with the Jew, “Hear, O Israel: The Lord our God is one Lord: and you shall love the Lord your God with all your heart, and with all your soul, and with all your might. And these words which I command you this day shall be upon your heart; and you shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise. And you shall bind them as a sign upon your hand, and they shall be as frontlets between your eyes. And you shall write them on the doorposts of your house and on your gates.”
Here in the clearest language is the teaching that God is one and that this teaching should be known by God’s people, talked about by them and taught to their children.
The same truth is in the New Testament, which is uniquely Christian. We read that “an idol has no real existence” and that “there is no God but one” (1 Corinthians 8:4). We are reminded of the fact that there is but “one God and Father of us all, who is above all and through all and in all” (Ephesians 4:6). James says, “You believe that God is one; you do well” (James 2:19).
One of our difficulties at this point is that we do not have an adequate word in English, or any other language, to express the nature of the different existences within the Godhead. We must not think of the persons in God being merely a way in which God from time to time represents himself to human beings. This particular error is known as modalism Sabellianism, from the name of the man who first popularized it about the middle of the third century.
The word most often used in the Greek language was homoousios, which literally means “one being.” But again, this is misleading if we begin to think that there are therefore three distinct beings with different natures within the Godhead. Calvin liked none of these words. He preferred the word subsistence. But, while probably quite accurate, nevertheless this word hardly conveys much meaning to most readers in our century.
Actually, the word person is all right, as long as we understand what we mean by a person. In common speech the word normally denotes a human being, and therefore one who is uniquely an individual. We have that concept in mind when we speak of depersonalizing someone. But that is not the meaning of the word as used in theology. It is possible to be a person entirely apart from our bodily existence. We may, for example, lose an arm or leg in some accident, yet we will still be a person with all the marks of personality. Moreover, at least according to Christian teaching, even when we die and our bodies decay to ruin we will still be persons. What we are really talking about, then, is a sense of existence expressing itself in knowledge, feelings and a will.
So there are three persons or subsistences within God, each with knowledge, feelings and a will. And yet, even here we are getting off the track. For in the case of God, the knowledge, feelings and will of each person within the Godhead -Father, Son and Holy Spirit – are identical.