When we approach the issue of the trinity, and what place does each aspect have, we need to use primarily the New Testament. The reason for this should be obvious. The Old Testament does give us some credence to believing in the trinity, but we cannot formulate the doctrine of the trinity solely upon the Old Testament. In all sincerity, I am more inclined to saying that we learn of the trinity from the whole revelation of God (Genesis through Revelation), and not only the Old or New Testament. But in the specifics, we simply don’t have it laid out for us in the Old Testament. Indeed, one of many of the offenses that Christianity has brought is to say that God is three in one.
Many of the Old Testament texts that hint at the trinity are not necessarily Trinitarian. That is not to say that we are incorrect in seeing God as three in Genesis 1 (Creator, Spirit, and Word), for example. It is only to make the point that we should be honest enough to admit that this doctrine is not obvious in the Old Testament. The Jewish people did not expect that God was a trinity until Jesus made such grandiose claims about Himself and the Holy Spirit. It was upon His teaching (Jesus’) that the Church came to believe in the trinity, and when going back to the Old Testament found that it is not incompatible (no contradictions). Even more so, they found that even though God is one, there are indeed slight hints at His being triune in the Old Testament, such as the before mentioned Genesis 1. From the Old Testament standpoint, God reveals Himself to humanity in many distinct manners, but does not necessarily reveal Himself as a trinity. Imagine if I were to try to express myself to someone who is two-dimensional. I could show them my length and height. I can should them my width and height. I can show them my length and width. In this, I show them three distinct “persons”, but all the while I am still one being. This is the way that the trinity is expressed in the Old Testament texts. Without the revelation of the New Testament, we don’t come to full conclusions.
So what are some of the texts that would tell us that God is indeed triune? Well, we simply need to expand upon those three points made earlier. What are the texts that say God is one? “Hear O Israel, the Lord our God, the Lord is one.” Isaiah 45:1, “I am the Lord, and there is no other; apart from me there is no God.” Joel also makes this clear in his second chapter verse 27. Deuteronomy 4:35, “You were shown these things so that you might know that the Lord is God; beside him there is no other.” We read in Mark 12:32, “You are right in saying that God is one and there is no other but him.”
The second point was that God has manifested Himself in three forms, and the third point was that all three exist alongside one another eternally. Lets start with the Gospel of John. This will in no way be exhaustive in any sense. John 1:1 tells us that “In the beginning was the word, and the word was with God, and the word was God.” John 3:13 says, “No one has ascended to heaven except he who descended.” Jesus asks in John 6:62, “What if you were to see the Son of Man ascending to where He was before?” In John 7:29, “I know Him (God), for I came from Him, and He sent me.” John 8:23 says, “You are from below; I am from above. You are of this world; I am not of this world.”
These are just a few Scriptures out of many in the book of John (not even going into the rest of the Scripture) to show that Jesus was pre-existing before He came to this earth. To establish His deity, Paul said in Colossians 2:9 that the fullness of God (KJV says Godhead, NASB says deity) dwells in Him (Jesus). John 12:41 states that Isaiah saw Jesus in His glory, but the problem for unitarians is that when you go back to Isaiah 6, the Hebrew is YHWH and not only Adonai. This says that Jesus was YHWH. Jesus says of Himself in Revelation 1: I am the alpha and the omega, the beginning and the end. A created being cannot say this.
What about the Holy Spirit? For some reason, everyone agrees that the Father is God. No one seems to imply that Jesus is God, and that the Father is something else. So I won’t spend time establishing the Father’s deity. In Acts 5, Peter claims that to lie to the Holy Spirit is to lie to God Himself (see verses 3-4). Many times in the epistles of Paul, the Holy Spirit is referred to as the “Spirit of God.” In 1 Corinthians 6:19-20, Paul asserts that our bodies are the temple of the Holy Spirit. Temples are for gods, not for created beings. Paul continues with explaining that both our body and also the Spirit within us are both God’s. God owns the temple, and it is God’s Spirit within us.
When you read the great commission, you read that Jesus tells us to baptize in the name of the Father, Son, and Holy Spirit. This both equates all with being God, and also makes the statement that each one is distinct. In the creation of the world, we find God as the creator, the Spirit, and the Word. God the Creator (the Father) used the Word as mechanism to create all things. Indeed, through Him (Jesus) were all things made, and without Him was nothing made. But the Spirit is what hovered over the waters. The Spirit’s role was to stir up the creation and give life, order, and form to everything that was created. God the Father created through the Son, and used the Spirit to give life and energy to all that exists.
Lets jump forward to modern times. If we grasp that God is three-in-one, what role do each aspect of the Godhead play? We can see in Creation how God the Father was the one who ordered everything into existence. Jesus, mentioned as the Word in John, was the mechanism for the creation of all things. The Holy Spirit was then the means by which everything was then ordered and given life. This is the same role and function that we see today. God the Father is the revealer of all knowledge of Himself. Jesus is the revelation (or mechanism) of that knowledge. The Holy Spirit is the one to animate and order that revelation. So we have God: Father, Son, and Holy Spirit, Revealer, Revelation, and the Revealing.
When we desire to know and understand each aspect of the trinity, we mustn’t come with any kind of preconceived notions about each aspect. If we think of God as the Father, we must allow the Scriptures to define what it means that God is the Father. Any father figure must conform to that revelation of God as Father, and we must never allow ourselves to skew the image of God by forcing Him into our concepts of what we think a father is supposed to be. God defines what it means to be a Father, and never the other way around.
Likewise, when we come to Jesus we mustn’t force our ideas upon Him. What does it mean that Jesus was the Messiah, or Christ? If we come with any kind of preconceived notion of what Christ is, then we have skewed the image of God. We must diligently protect God as He is. Thus, Jesus is the sole definition of what it means to be the Messiah, and never the other way around. He alone is the mechanism by which God the Father has revealed Himself. Any other basis by which we attempt to know Jesus is a false basis. If we desire to split the Bible and say that the God of the Old Testament is full of anger and wrath and judgment, we not only commit heresy, but also blaspheme. This same God that we read of in the Old Testament is the man Jesus that comes lowly riding upon a donkey. He is the full embodiment and expression to humanity of who God is, and what God is like.
Finally, our idea of what the Holy Spirit is like, what its role is, who it is, why it is, etc are not to be understood by our fanciful imagination. Scripture defines each aspect of the trinity. The Holy Spirit is to be known and understood in the way that He acts and reacts with us. The Holy Spirit is the one who stirs up within us the revelation of the knowledge of God. To pervert the Holy Spirit by making it an object of hype and spiritual animation through dubious gifts is to rob God of His essence. This is the very presence of God. It is worse than not doing rightly to even think that the Holy Spirit is somehow our bellboy, and only a command in the name of Jesus away.