The doctrine of the Trinity is a foundational cardinal truth in Christianity. All three major Christian traditions – Protestant, Roman Catholic, and Eastern Orthodox – throughout the history of the Church, have been united on this doctrine. A denial of it constitutes a serious departure from the Christian faith and a rejection of the biblical witness to God as he has introduced himself to us. Sadly, many go astray from the faith due to their refusal to accept these truths. It is my purpose to give a brief overview of the doctrine.
Basic Definition: Christians worship one God who eternally exists in three persons, God the Father, God the Son, and God the Holy Spirit, all of whom are fully God, all of whom are equal.
Now let’s break each of these down.
Christians are monotheists. This doesn’t merely mean we worship only one God, but that we believe there exists only one God. This is a basic teaching throughout the Bible (Deut. 6:4; Isa. 44:6; Isa. 45:5; Mark 12:29; 1Tim. 2:5; 1Cor. 8:4).
While this finds support in the Bible, the very definition of God demands that there only be one. In other words, “God” is not just a being to whom you pray or ascribe great worth and value, but the transcendent creator of all things (Heb. 11:3). Romans 1:18-20 informs us that natural theology and rational thinking necessarily demand there be a singular source for all things. Polytheism (which is the belief in many gods) must redefine the term “god” to mean simply “really powerful beings,” since there cannot be many ultimate creators of all things. There can be only one Uncaused Cause, only one Unmoved Mover, and only one Uncreated Creator. God is the only non-contingent (not dependent) being in the universe. Therefore, his essence is necessarily one.
Eternally exists as three persons:
Christians do not believe in contradictions or logical fallacies. Rational thinking and harmony of truth are found in the essence of God’s being; therefore, God cannot exist as a contradiction. Christians do not believe in three Gods for the reasons listed above. However, we do believe Scripture has revealed that God, while one in essence, is three in person. We often talk about this as “one what, three whos.” While this is a great mystery in the Christian faith, there are many mysteries that we are compelled to believe due to necessity and what has been revealed in Scripture. For example, we believe that God created all things out of nothing (Heb. 11:3; doctrine of creation ex nihilo). We believe that God is the sovereign first cause of all things, yet man is morally responsible for his actions. We believe that while Christ was complete in his humanity, he also remained complete in his deity (often called the “hypostatic union”). We believe that the Bible is the product of humans and the product of God. None of these, including the doctrine of the Trinity, are contradictions, but they are great mysteries.
While the Bible does not use the word “Trinity,” we believe that it is an accurate description of what the Bible teaches concerning God. After all, the Bible does not use the word “Bible,” but we can legitimately use the word to describe a collection of books we believe to be inspired. The Bible does not use the word “aseity,” yet we believe that it accurately represents a Biblical attribute of God. God is “of himself,” in no way dependent upon humans for his livelihood (Ps. 50:7-12).
While there are many passages in the Bible which necessitate a Trinitarian understanding of God, there are a few that stand out more than others:
“In the beginning was the Word, and the Word was with God, and the Word was fully God.” (NET)
Here we encounter two subjects, “the Word” (Jesus; John 1:14), and “God.” We see in this one verse the unity and plurality in what we call the “Godhead.” The Word “was fully God,” yet we also see that they were “with” each other. The Greek word for “with,” pros, implies not merely proximity, but is used to describe the context of relationship in which they exist. Jesus and God (in this case God is “the Father”) are both sharing in the same essence of deity, yet are distinct in relationship (person).
“Therefore go and make disciples of all nations, baptizing them in the name of the Father and the Son and the Holy Spirit.”
This is often referred to as the “Great Commission.” Here Christ tells his disciples that they are to make disciples by baptizing them (as a sign of identification) in the name (a singular term describing God’s unity) of the Father, Son, and Holy Spirit. Notice that all three members of the Trinity are united, yet distinct in this baptismal creed.
“Philip said, “Lord, show us the Father, and we will be content.” Jesus replied, “Have I been with you for so long, and you have not known me, Philip? The person who has seen me has seen the Father! How can you say, ‘Show us the Father’?”
This again speaks of the unity the members of the Trinity share with each other. To know Jesus is to know the Father. To know the Holy Spirit is to know Jesus and the Father. And to know the Father is to know Jesus and the Holy Spirit. They are all one. Yet in the very same section of Scripture, Jesus demonstrates that He and the Father are distinct persons by praying to the Father (John 17:1-26). They have been united and distinct for all eternity.
All of whom are fully God:
Don’t see the sharing of the divine essence as some sort of sharing in a type of nature. For example, my daughter Kylee and I share in a similar nature in two ways: 1) we are both humans and 2) we are both blood related as part of the “Patton” family. God the Father, God the Son, and God the Holy Spirit do not merely have similar natures. It is not that they are from the same species called “God” or “Divine.” It is not like a pie that has been cut into three pieces, or a three-leaf clover that can be divided into three parts. It is that they all have the exact same nature. Kylee and I are of the human species, but we do not share in the exact same essence. God’s essence is one and indivisible. All the members of the Trinity are all fully God since they share in the exact same nature..
All of whom are equal:
Christ’s essence is not lesser than the Father’s, nor the Spirit’s lesser than Christ’s. They are co-equal, co-powerful, and co-eternal since the essence of who they are is the same. While their persons may have distinction in function and thus evidence a willing hierarchy in time (John 14:28) and in eternity (1 Cor. 15:23-28), this does not mean that one is greater than the other in essence. Just as a king may have authority over his subject, this does not mean the king’s nature is greater than the subject’s. And just as a wife is to submit to her husband (Eph. 5:22), or as a pastor has authority over the congregation (Heb. 13:7), this does not mean in either case that the husband or pastor has more essential greatness or value than the wife or congregation. It simply means that in function, there is a hierarchy. Some Christians believe that the hierarchy in the Trinity was a temporal arrangement for the purpose of redemption and some believe that the subordination of the Son to the Father and the Spirit to the Father (and Son) is eternal. This is a valid debate in Christianity. However, all Christians have always believed that all three members of the Trinity are essentially equal.
Concerning the use of the word “Trinity”
Concerning the use of the name “Trinity” and other technical terms we often employ such as essence, ontos, ousia, substantia, persona, or hypostasis, the great theologian of the sixteenth century John Calvin writes:
“Where names have not been invented rashly, we must beware lest we become chargeable with arrogance and rashness in rejecting them. I wish, indeed, that such names were buried, provided all would concur in the belief that the Father, Son, and Spirit, are one God, and yet that the Son is not the Father, nor the Spirit the Son, but that each has his particular subsistence. I am not so minutely precise as to fight furiously for mere words. For I observe, that the writers of the ancient Church, while they uniformly spoke with great reverence on these matters, neither agreed with each other, nor were always consistent with themselves” (Institutes, 1.13.5).
No Christian understands the doctrine of the Trinity fully. In fact, if people are not confused to some degree by this doctrine, if someone says, “Ohhhh, now I understand,” it probably means they have slipped into heresy in their thinking. If we think about it too long, try to solve it, or nuance it according to our desire to comprehend things, we will find ourselves refusing the hand of God who has given the mysterious Trinity to us as a description of Himself. While it is impossible that finite beings can fully comprehend an infinite God, we can understand him truly. The doctrine of the Trinity does not give us the full understanding of God, but it does give us a true understanding of God.