What is Christian doctrine? To put it another way, what does it mean for a Christian to hold a doctrine? After all, many Christians seem to be doctrine-holding people, do they not? Some doctrines seem more foundational, more widely held, such as the doctrine of the Trinity or the doctrine of sin. Others, though, seem more particular, perhaps observed by one denomination but not another, such as the doctrine of the immaculate conception or the doctrine of double predestination. Setting the specific doctrines aside for just this essay, what does it mean for a Christian to hold a doctrine at all?

A brief etymological sketch will help us begin. Our English word doctrine comes directly from the Latin word doctrina, which means teaching. So, when we speak of doctrine, we speak of teaching, and therefore, not only are they the doctrine of the Trinity and the doctrine of sin, but also, the teaching of the Trinity and the teaching of sin. Notice that, instantly, we see this term with far more energy. Doctrines do not form a lifeless list of terms and definitions awaiting our assent or dissent. Rather, doctrines are activities, processes with subjects and objects––indeed, teachings. But this sense of doctrine as teaching only leaves us with more questions: if a doctrine is a teaching, then just what is being taught, and just who is the teacher?

First: just what is being taught? God Himself is the only subject matter of doctrine. This might seem simple enough, especially for something like the doctrine of the Trinity, which is clearly about who God is, but it becomes more complicated when we take up those doctrines that focus on human affairs, such as the doctrine of sin. Surely, God is not sinful! How do we make sense of this? Since the only subject matter of doctrine is God Himself, even though a doctrine seems to be focused on humankind, it is actually about God. The doctrine of sin, for instance, is about humankind insofar as sin is the human rejection of God. In this way, each and every doctrine’s proper subject matter is God. Sometimes, this includes those things that are related to God, but always and only for that reason.

Now, second: just who is doing the teaching? Is the theologian the true teacher of doctrine? What about the pastor or the preacher? Or perhaps the pontiff, or a denomination’s governing body? Interestingly enough, not one of these. The One and Only True Teacher is God Himself. And why is that? God is, by definition, something beyond nature, beyond the world of our senses. Thus, we could say that God is supernatural, literally beyond nature. As such, we cannot learn of God the same way we would learn anything else, like learning that autumn has come because we feel the cool breeze on our skin and see the leaves changing in color. This is how we learn of the natural, but this is not how we learn of the supernatural. Learning of supernatural things is beyond our natural ability. Therefore, if we are going to learn of who God is, it will only be when God chooses to teach us. The technical term for this phenomenon is revelation, and it is on this revelatory act of God that all of Christian theology stands: Christian doctrines are those things about God that are taught to us by God. In this way, doctrine is revelation, God’s sovereign and loving choice to reveal Himself to His creation––that is, you and me. So, a doctrine is a teaching, yes, but specifically, a teaching about God that is taught by God.

But this leaves us with a problem: would not even this sense of doctrine, this sense of doctrine as teaching about God from God, need to have been revealed to us by the One True Teacher? Most certainly! But this is no easy matter. In fact, this brings us to the central puzzle of revelation and doctrine: in what ways does God reveal Himself? Just how do these doctrines, these teachings, come to us? Foundationally, the Christian faith acknowledges that the work of doctrine, the work of God teaching us about Himself, occurs through Holy Scripture. So, yes, even this teaching sense of doctrine must have been revealed to us, and thus, we now turn to the sacred writings themselves.

We begin our journey at Mount Horeb, elsewhere in Scripture styled Mount Sinai. There, we find the Scriptural foundation of this teaching sense of doctrine. There, we learn––notice this way of learning from God through Scripture!––of how the Living God graciously chose to reveal Himself to Moses, the one who would then lead Israel out of Egypt and who would ultimately become the greatest prophet. This makes up the “first act,” as it were, of the book of Exodus: the LORD God seeing His people’s suffering and then interceding, delivering them so that they might serve Him in the wilderness. And the centerpiece of this “first act,” and, indeed, perhaps of the entirety of Israel’s Scriptures, is the LORD’s decision to reveal Himself to Moses upon the mountain:

… Moses said to God, “If I come to the Israelites and say to them, ‘The God of your ancestors has sent me to you,’ and they ask me, ‘What is his name?’ what shall I say to them?” God said to Moses, “I AM WHO I AM.” He said further, “Thus you shall say to the Israelites, ‘I AM has sent me to you’ … This is my name forever, and this my title for all generations.” (Exodus 3:13–14, 15b)

God teaching His Name to Moses is a pivotal moment. This is the moment in which the LORD discloses who He is and what He will do for His people, that He is the One “who will be who He will be,” another way of translating His Name. This Name, this Divine Name, reveals the limitless and undefinable depth who is God Himself, the One who will redeem His people from Egyptian bondage in His own glorious ways. Here, God teaches Moses who He is, and He Himself does so in His Own voice spoken through a bush, blazing but not consumed.

But this is not the only instance of the LORD God revealing Himself to Moses upon this particular mountain. Several chapters later in the book of Exodus, after the Israelites have been freed from Egyptian bondage, the LORD descends upon Sinai:

On the morning of the third day there was thunder and lightning, as well as a thick cloud on the mountain, and a blast of a trumpet so loud that all the people who were in the camp trembled … Mount Sinai was wrapped in smoke, because the LORD had descended upon it in fire; the smoke went up like the smoke of a kiln, while the whole mountain shook violently … Then the LORD said to Moses, “Go down and warn the people not to break through to the LORD to look; otherwise many of them will perish.” (Exodus 19:16, 18, 21)

This scene teaches us just how overwhelming it is for God to reveal Himself, to break into our creaturely scene. God’s teaching upon the mount is inaccessible because it is so very beyond us, so very supernatural, so much so that it can actually be dangerous if one is not careful. As such, Moses is charged with helping to mediate the revelation of God to the rest of the people. And in this way, the LORD begins to reveal His Torah, His teaching, inaugurating the entire legal edifice that will guide the people of Israel into their life with the One God Who has chosen to teach them. Much of Israel’s Scriptures speak of longing for this Torah, this teaching, particularly the Psalter, which so often prays that God might teach us His ways. All of this, this entire sense of God teaching His people about who He is and who they are in relationship to Him, together with His people’s longing to learn of the same, is what we mean by the term doctrine, and it begins on this holy mountain in the wilderness of old.

But there is more! For you see, this teaching continued on yet another mountaintop and through yet another son of Israel, Jesus of Nazareth. The Gospel of Matthew, the first of the four Gospels in the New Testament, recounts a particular scene of Jesus Christ teaching His disciples atop a high place: the “Sermon on the Mount,” as we now know it. It is a scene that is inherently related to its sister scene, the LORD God of Israel teaching upon Horeb in Exodus. In this way, Jesus is portrayed as a kind of “second Moses,” teaching the things of God to His people. It is here, for instance, where Christ teaches the Beatitudes: “Blessed are the poor in spirit, for theirs is the kingdom of heaven” (Matthew 5:3), and it is here where our Lord first teaches us His prayer: “Our Father in heaven” (Matthew 6:9).

But notice the difference between this mountaintop moment and that of Exodus: Christ speaks this teaching Himself. The beginning of the Sermon on the Mount insists on this: “[Jesus] began to speak and taught them” (Matthew 5:2). Here, we see the dramatic force of the Christian conviction that Jesus of Nazareth is the enfleshed Son of God, revealing God’s self to the world. Indeed, here, we find God Himself teaching us. But rest assured, just because there is no thunder, lightning, fire, and smoke at Sinai, this revelation of God, this teaching from God about God, is no less otherworldly, no less dangerous––that is, dangerously different to the ways of this world. After all, Scripture tells us again and again that Christ’s teaching astounds those around Him:

Now when Jesus had finished saying these things, the crowds were astounded at his teaching, for he taught them as one having authority, and not as their scribes.      (Matthew 7:28–29)

Indeed, God must be the One to teach us about Himself, because He is utterly and uniquely Other and, thus, we cannot learn of Him on our own. In Jesus Christ, we find this utterly unique True Teacher in our midst: Immanuel, God with us.

And if we take the Incarnation––God taking on flesh as His own––seriously, then this teaching sense of doctrine appears not only in Christ’s words, but in His flesh and blood, His living and dying, and everything in between. Jesus Christ is living and breathing doctrine, the True Teaching of God walking throughout the Galilee. His lowly birth in Bethlehem teaches us, as does His healing the sick, His dining with sinners, His feeding the multitudes, His blessing little children, and yes, even His willingness to be betrayed, His night in police custody, His torture, His crucifixion, and His resurrection. All of this is what we mean by doctrine, that God willingly and actively chooses to teach us about who He is and about who we are in relationship to Him, and He definitively does so in the person of Jesus Christ.

After His resurrection, the Risen Christ meets His disciples atop yet another mountain, a central setting, as we have seen, for these moments of Divine teaching, a commonality that fastens each scene to the other. He says to them:

Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything that I have commanded you. (Matthew 28:19–20a)

In this scene, the “Great Commission,” as we now know it, the Risen Christ commands His disciples to teach others what He had commanded them. Until this moment, the Gospel of Matthew reserves the role of “Teacher” to Christ alone. At one point in which Christ sends out His twelve disciples to take their part in His ministry, He gives them “authority over unclean spirits, to cast them out, and to cure every disease and every sickness” (Matthew 10:1), but notably, He does not give them authority to teach, which does not happen until the Great Commission. In this way, our work of teaching, of doctrine, is one of stewardship, being invited to share in the work that chiefly and solely belongs to God.

The Great Commission is the turning point, the moment when we move toward doctrine as we often experience it in the Christian faith today: doctrine as God’s teaching about Himself, yes and always, but now, also, doctrine as a task of the Church. The Church is to teach that which we have been taught. Doctrine, then, is absolutely essential work, not least because it has been commanded by the Lord Himself. This essential work is the work of interpretation, to articulate just what it is that God has taught us, which leads to a variety of conclusions, such as the doctrine of the Trinity or the doctrine of sin, but also ones that are not as commonly held, such as the doctrine of immaculate conception or the doctrine of double predestination. We pray that God might guide us to interpret faithfully what He teaches us about Himself––and, indeed, interpret we must, for this is the task of the Church.

And here, we can see just how potentially frivolous this work is. We can see how easy it is for Christians to hold different interpretations of the teachings of God, and we can see how this can become so deeply divisive. After all, these are not simply differences of opinion, things that can be held lightly, but rather, different convictions of just what Almighty God teaches us about Himself. So, not only is it natural for there to be difference, because interpretation inherently produces difference, but it is also natural for there to be tension amongst the differences, because, after all, these are convictions about the deep things of God. But we should be quick to recognize that the Church’s work of interpretation is a collective effort. Notice that Christ gives the Great Commission to His disciples as a united whole, not to each individual person. The task of doctrine is a task that we share, principally with the True Teacher, yes, but also with one another.

This quiet, unassuming word, “doctrine,” carries a bold conviction of its own, that God has decided to teach His creation about who He is and about who we are in relationship to Him. He teaches us in the writings of Holy Scripture. He teaches us in a burning bush and in the prophetic voice. He teaches us in His Own Self, in the life, death, and resurrection of Jesus Christ. The Church’s task to meet Him in His teaching, therefore, is a humbling one: is there anything more beautiful, more demanding, than to be taught by God? The Church’s prayer should always be that we listen for the Good Teacher with clarity, collegiality, and faithfulness, that we might take up our work of passing His teaching on, just as He would have us do.