Defining Orthodoxy, Adoring Mystery

How to Teach the Doctrine of the Trinity in Your Local Church

Trinity Sunday in 2024 is May 26 but it is never too early to start thinking about preaching the doctrine of the Trinity in your local church. I want to suggest a four-part roadmap to preaching or teaching the doctrine of the Trinity to lay people through sermons, Sunday school lessons or other methods. I am not offering a canned approach and, trust me, there are no corny illustrations in this article. That means no water, no clover, and certainly no dad/doctor/husbands.

What I am going to suggest could best be described as a strategy to introduce the doctrine to those who either are new to the faith or who should know about it but (let’s be realistic here), just don’t have a clue. You cannot make deep theologians out of novices in half an hour, but you can introduce the topic, set some basic parameters for understanding, and encourage your listeners to see the value of going deeper.

Enough preliminaries. Where to start?

Step One: Make it More Complicated

This may seem counter-intuitive but hear me out. The goal here is to ensure that nobody underestimates the severity of the problem of thinking about what it means for God to be one God in three persons. All the easy answers are wrong.

In our churches today, the problem is not that most people have never heard of the doctrine of the Trinity. Everyone knows that there is one God and that the Father, Son, and Holy Spirit are God. The problem is that many people mistakenly think that they believe in the doctrine of the Trinity when, in reality, they are tritheists or modalists.

Discussing the main heresies, especially tritheism and modalism, can drive home the point that the heresies exist because it is so easy to go wrong when putting this doctrine into words. The Trinity is not a committee nor a group of three close friends. The Trinity is not one God playing three different roles at different times. It is more complicated than that. 

So, step one is to show that no easy solutions are available.

Step Two: Make it Clear that We Do Not Believe a Contradiction

At this point things can easily go off the rails and people can despair of ever being able to avoid error. Maybe nobody gets it right. Maybe it really doesn’t make sense. In our current cultural climate, many are ready to embrace irrationality. Don’t let them jump off that cliff.

The key to step two is to stress that we are not asking anyone to believe in a contradiction. Distinguish clearly between a contradiction and a paradox, which is an apparent contradiction. If it is only an apparent contradiction, then it is not a contradiction at all. Hammer this point home because it is crucial.  

Talk about how reason and faith go together and help each other and that while we should not expect it to be easy to understand God, we should expect that we never have to sacrifice our intellects to believe Christian doctrine. The finite human mind should not expect to be able to comprehend the infinite God completely, yet we can know some truth about God because of general and special revelation. We can believe what God has revealed about himself and, as far as it goes, it is true. We can apprehend without comprehending. We can have true truth without having exhaustive truth.

Now we are set to dive into the meat of the doctrine.

Step Three: Describe the History of the Doctrine

Having established that this doctrine is complex and yet not nonsensical, we are ready to engage the positive truth it states. At this point, my advice is to tell a story. Go back to the early church and take them through the stages the historical church went through in thinking through the problem.

The disciples were monotheistic Jews who were trained by their immersion in the Old Testament to reject Greco-Roman polytheism. They knew that there is only one true God: Yahweh, the God of Israel. They not only knew this; it was ingrained into every fiber of their being from birth. They knew it as a result of their people having assimilated (albeit not without much resistance) a thousand years of Divine revelation.

But they were confronted with a man who appeared to be the Messiah and who did and said things that could only be done and said by God. He did miracles, displayed Divine wisdom, and corrected the religious teachers’ interpretation of the law by claiming to understand God’s purpose in giving it. He presumed to call people to believe in him and trust him for salvation (John 14:6). To top it all off, he rose from the dead and ascended to heaven in front of their very eyes! No wonder the New Testament shows them confessing faith in him as Son of God, as when Thomas said, “My Lord and my God” (John 20:28).

Then look at the way the earliest Christian communities sang hymns like the one in Philippians 2 and began to worship Jesus even though they knew full well that worship belongs only to God. They did it before they fully grasped the full implications of what they were saying.

The church fathers presupposed this faith in Jesus as man and God in their teaching and reflection, and they worked hard to figure out to describe what it means to believe in Jesus in the full Biblical sense. They wrestled strenuously with the problem they had inherited.

The early church knew two things for sure: 1) that Yahweh is the only, one, true God, and 2) that Jesus the Messiah is Yahweh. Any doctrine of the Trinity would need to affirm both truths without allowing one to be watered down in order to highlight the other. They rejected those heretics who denied the full humanity of Jesus like the gnostics, and they also rejected those who denied the full deity of Jesus like the subordinationists.

By the fourth century the church was adopting technical metaphysical language to make the points ever more precise. Arius came right out and said that the Son is subordinate to the Father as the first and greatest creature of the Father. The Arian crisis revolved around the meaning of the Biblical language of “Father” and “Son.” If the Son is a son, how can he be equal to the Father? Or is he really equal? The orthodox church fathers said, in response to Arius, that we must affirm the full equality of the Father and Son and rule out all subordinationism. The problem was finding a way to state it in such a way that could not be twisted and given a subordinationist interpretation.

In the ancient world it was not enough to say that Jesus is divine because many different degrees of divinity were part of the polytheistic mindset. Jesus could be divine and yet not equal in glory and majesty to the Father. The Arians thought that was fine because it preserves monotheism. The orthodox church fathers, however, saw it as blasphemy against the Son (and Spirit).

What was the solution? In the Nicene Creed the word ousia meaning substance or being was used to describe what there is one of in God. The word hypostasis, (which had previously been practically a synonym for ousia) was used to describe what there are three of in God. So, the key formula was created: one ousia, three hypostases. In English we say God is one being, three persons. The Father, Son, and Holy Spirit are three persons (hypostases) and they are one, common, being (ousia).

Step Four: Present the Positive Implications of Mystery   

The final step is to explain the purpose of the Nicene Creed. The purpose is not to explain rationally the nature of God. The purpose is to say what we must affirm in order to be interpreting the Scripture properly. It is to define the doctrine of the Trinity but not to reduce the mystery to what can be rationally understood by mere humans.

The formula “one being, three persons” shows that what we are asked to believe is not a contradiction. It would only be a contradiction if being meant exactly the same as person. Then it would be saying that we must believe that God is both one and three in the same way at the same time. But there is a distinction between “person” and “being” that is more than terminological.

So, someone is bound to ask, “What exactly is the distinction?” The answer given in fourth-century, pro-Nicene theology is that the only distinction we can name is the one implicit in the names given to the Divine Persons in Holy Scripture and that is the eternal relations of origins. The Father eternally begets the Son and the Father and Son eternally breath out the Spirit. That is how they are distinguished. Here we reach the limits of human knowledge of God. This is the edge of mystery. Beyond this point no human being can go.

But the fact that the doctrine of the Trinity is a mystery is precisely what we should expect of a human attempt to describe the infinite, personal God. We should expect, with Augustine, that if you can define it, it isn’t God. We should respond to the mystery with worship. The doctrine of the Trinity is meant to humble us, and we need to bow before the majesty of our Creator and cry out with the seraphim: “Holy, holy, holy is the LORD of hosts; The whole earth is full of his glory!” (Isa. 6:3)

Only then do we confess the orthodox doctrine of the Trinity.