That is an appropriate verse to begin this discussion on the doctrine of the trinity. Why is that such an appropriate verse? Because it explains a very important point to remember when it comes to God and the study of him (theology). We can learn a lot about God and who he is, but we will never be able to fully comprehend him this side of eternity. Biblical scholars have been debating the doctrine of the trinity for centuries. This is because it is a difficult teaching to understand. Some would like to nail it down and put God in a box while others don’t even attempt to understand it all. I hope that after reading this post, you will be able to walk away with a much better grasp of what the doctrine of the trinity is. However, I also know you will still be left scratching your head. Just know that is okay—see Isaiah 55:8-9 above.

In general, the first objection people make against the trinity is that those who hold to this teaching are making something out of nothing because the word “trinity” is never used in the Bible. How should one respond to that? By stating that they are correct of course; the word trinity itself is never used in the Bible. The word was originally coined by a third century theologian, Tertullian, who used the Latin term trinitas, when translated to English becomes trinity. It was a compound word taken from the two root words trinus (meaning three-fold) and unus (meaning one); forming the understanding of a three in one or tri-unity. However, just because the word trinity is never found in the Scriptures does not automatically preclude the doctrine from being biblical. The understanding of the trinity is found throughout the Bible in both the Old and New Testaments.

What does the Bible teach about the Trinity?

The Bible presents three facts or points concerning the trinity. The first fact which the Bible presents is that there is only one God. A concept that few would claim is not made by the Scriptures. The second fact is that God is three persons. This idea is debated among differing sects of Christianity to exactly what that means. The final and third fact is that each person is fully God. Nearly every Christian would agree intellectually to this statement, but do not express it as such when living out their beliefs in everyday life.

Probably the most popular passage to use when talking of the oneness of God is Deuteronomy 6:4-5, “Hear, O Israel: The Lord our God, the Lord is one. Love the Lord your God with all your heart and with all your soul and with all your strength.” This passage of Scripture is one of great importance to Jews and became known as the Shema (pronounced: sh•mā), which is translated to “hear” in English and begins this passage. As we know the rest of the story, it is clear that God wanted the Israelites to truly “listen up” and take to heart that he was the only God since they would spend much of their time as a nation worshiping other deities. There is a verse in the gospel of John that has been deemed as the New Testament Shema, if you will. It is John 10:30 when Jesus is debating with the Pharisees and makes the statement, “I and the Father are one.” Thus, indicating that he thought himself equal to God.

There is a vast range of Scriptures one could cite to demonstrate that God is one person. So in the interest of maximizing the limited nature of a blog post, I am not going to spend time going through the Scriptures on this point. Especially since this is not a huge point of debate concerning God. However, the next point is one which has brought about much debate.

The Bible teaches that God is in fact three persons. Genesis gives several instances of the plurality of God. In the opening verses of the Bible, it is clear that there are at least two persons in the Godhead. Genesis 1:1-2—“In the beginning God created the heavens and the earth. Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.” So right away we see “God” and the “Spirit of God.” Later in the opening chapter, God speaks of himself in the plural tense. Genesis 1:26—“Then God said, ‘Let us make man in our image, in our likeness, and let them rule over…’” And again in Genesis 3:22—“The man has now become like one of us, knowing good and evil.”

If that’s not enough from the Old Testament, even Deuteronomy 6:4-5 mentioned above speaks to the plurality of God. The Hebrew words have a meaning that is richer than the English translation exhibits. When we read, “the LORD our God, the LORD is one” there are very specific words used, which betray the strict understanding most take away from this verse. The "LORD" is the Hebrew word Yahweh. This is the covenant name of God used only to describe the Living God; the God of Abraham, Isaac, and Jacob; the God of the nation Israel; and the creator of the universe.

Elohim is the second major word used and is translated as "God" in English. This word is a less specific word to describe God. Where “LORD” was very specific as to whom it was referring, Elohim was a broader term that could have been used in reference to other gods as well. However, the important thing to note about this word is its conjugation. It is in the plural conjugation of the word. This is difficult for many people who only speak English because there is no equivalent construction when conjugating words. An example from Spanish may help some people to understand what I am talking about. When using a word in Spanish, such as caminar (to walk), it can be constructed in the first person singular—camino (I walk), second person singular—caminas (you walk), third person singular—camina (he/she walks), first person plural—caminamos (we walk), or third person plural—caminan (they walk). This word spoke directly to the plural nature of God, the LORD.

The third important word to make note of is “one.” In the Hebrew it is echad and it expresses the understanding of a plurality of things coming together as a singular unit. Let me give you an illustration of what this means. It is similar to using the word “automobile.” Anyone hearing that word understands the person to be speaking of a singular thing—a pickup truck, sedan, van, etc. However, an automobile is actually made up of thousands of parts: tires, rims, pistons, lights, seats, etc. No one would try to describe it in that fashion though—“I have four tires and rims, eight pistons, a windshield, two headlights, etc.” It is simply easier to tell someone you have an automobile and they know that you are talking about a singular item which has all of those individual parts as well. Deuteronomy 6:4 expresses that Yahweh, the covenant God of Israel and creator of the universe, is a plurality coming together as a singularity.

Genesis 18 contains an illusion to the Godhead being comprised of three persons. When the LORD visited Abraham at the great trees of Mamre, there were three visitors. In the New Testament, Jesus’ baptism marks the appearance of God the Father, God the Holy Spirit, and God the Son at the same time (Matt. 3:16-17, Mark 1:10-11, Luke 3:21-22). Likewise, we find Trinitarian statements in the Scriptures as well (Matt. 28:18-20).

When it comes to the three person of the trinity, each is person 100% equal and 100% deity. What do I mean by that? Most Christians impose a hierarchy upon the trinity. They place God the Father at the top of the ladder, so to speak. Then the Son is the next on the totem pole followed by the Holy Spirit bringing up the rear. The Scriptures are clear on this point. The Father is called God throughout the Scriptures (2 Peter 1:17, Malachi 2:10). Not only does Jesus make the claim himself, but he is called God as well (Philippians 2:5-11, Colossians 2:9). Scripture does not leave the Holy Spirit out of this line-up either. In Acts 5, the apostle Peter places the Holy Spirit on equal footing with God the Father in his statements to Ananias. John 16:8-11 also clearly places the Holy Spirit on par with the rest of the Godhead as it credits him with being able to perform things only reserved for the LORD.

The briefest way to explain the trinity is summed up in these three points: