Perhaps one of the greatest testaments to the strength of the doctrine of the Trinity (with the obvious exception of the fact that it is taught in Scripture) is the simple fact that no one who opposes the doctrine seems to be able to understand it. According to such heretics, the doctrine of the Trinity is impossible because the Bible says there is only one God. The problem with this, however, is that so does the doctrine of the Trinity. Contrary to popular opinion, the Trinity is not a trio of Gods, but rather, one single God, who exists in 3 separate, coequal persons. The Father is God, the Son is God, the Holy Spirit is God.
But no matter how many times you explain this to a heretic, they never seem to understand. They always argue against the Trinity on the basis of monotheistic Scriptures. So, although I have written on this topic before, I thought I would do so again, this time with illustrations.
Suppose we could draw a circle, and write within it everything about God. Now of course, you’re going to find “complex and unknowable” inside this circle. But you’re also going to find everything God has revealed to us about Himself in Scripture.
Let's begin with a few simplistic examples. We can begin with the obvious God as Creator. God is love. God is eternal. God is perfectly Holy. Things like this can all go in the circle of things we know about God.
Now, up to this point, we're talking about the same God, right? There is no second God here, and indeed, there could never be. "“You are My witnesses,” says the Lord, “And My servant whom I have chosen, That you may know and believe Me, And understand that I am He. Before Me there was no God formed, Nor shall there be after Me." (Isaiah 43:10). Thus, we can add the oneness of God into our circle.
Now let's draw another circle, and in it, we write everything we know about Jesus. The possibilities for where I could go from here are endless. Of course, once again, I can simply begin with the basics. I can say He was born of a virgin. I can say He was a human being. I can say He performed miracles, never sinned, and died on a cross. These are all things anyone should know about Jesus, so in they go to our circle.
Now, already, at this point, I could do heretics really dirty and add "He is the Son of God" to our circle. In so doing, I would necessarily have established His divinity. How? Let me ask you, what is the son of a duck? It's obviously not an alligator. What about the son of an alligator? Probably not a tapir. What's the son of a tapir? Only a contrarian would say a jaguar. Sons naturally take on the nature of their fathers. Thus, if Jesus is the Son of God, what is He? "A" God. Yet, there can only be one God.
But there are sneaky ways around this, up to and including the fact that, by virtue of adoption, we are also sons of God. Christ is unique in His own Sonship, but through the cross, He has made a way for us to be adopted as sons and daughters of the Living God, yet we do not become Gods.
To this, I simply say this very issue was discussed roughly 2,000 years ago. In John 10:30-39, we read "I and My Father are one.” Then the Jews took up stones again to stone Him. Jesus answered them, “Many good works I have shown you from My Father. For which of those works do you stone Me?” The Jews answered Him, saying, “For a good work we do not stone You, but for blasphemy, and because You, being a Man, make Yourself God.” Jesus answered them, “Is it not written in your law, ‘I said, “You are gods” ’? If He called them gods, to whom the word of God came (and the Scripture cannot be broken), do you say of Him whom the Father sanctified and sent into the world, ‘You are blaspheming,’ because I said, ‘I am the Son of God’? If I do not do the works of My Father, do not believe Me; but if I do, though you do not believe Me, believe the works, that you may know and believe that the Father is in Me, and I in Him.” Therefore they sought again to seize Him, but He escaped out of their hand."
Notice, first of all, that by claiming He is one with the Father, the Jews immediately recognised that He was making a claim to divinity. "“For a good work we do not stone You, but for blasphemy, and because You, being a Man, make Yourself God.”" How? By claiming to be one with the Father. Note, one with the Father. Not two separate Gods, one. This is what we, as Trinitarians, believe. But I digress. In response to their charge, Jesus doesn't correct some sort of misunderstanding. Rather, He doubles down, citing Psalm 82:6. If, He reasons, those to whom the word of God came can be legitimately called "gods", how much more can Jesus, the Son of God, claim to be one with the Father?
But even here, a heretic can be sneaky and suggest that the Jews weren't exactly the world's most sophisticated theologians. They were, after all, about to murder Jesus. Next question: Is God a good theologian? Pay attention to Hebrews 1:5-8: "For to which of the angels did He ever say: “You are My Son, Today I have begotten You”? And again: “I will be to Him a Father, And He shall be to Me a Son”? But when He again brings the firstborn into the world, He says: “Let all the angels of God worship Him.” And of the angels He says: “Who makes His angels spirits And His ministers a flame of fire.” But to the Son He says: “Your throne, O God, is forever and ever; A scepter of righteousness is the scepter of Your kingdom."
Wait... So, God calls the Son (i.e. Jesus) "God", tells all the angels of God to worship Him, and establishes His throne forever? Well, if the infallible God, who cannot lie, is telling us that Jesus is God, then we have no option but to add "God" to our Jesus circle. But now we have a problem. We have two God circles, yet the information inside the "God" circle tells us there can only be one God circle.
So what's the solution here? Is there a contradiction? Is God a liar when He says there will only ever be one God? Or is He lying when He calls the Son God? Well, Jesus gives us the solution: "I (the God whose throne is established forever) and the Father (the God who says this to me) are one." They are one whole God! Not two Gods, not two halves of God, one whole God! So, what do we do? We merge the circles! Everything we know about Jesus goes into the everything we know about God circle.
But here's where it gets complicated, because we don't actually need to dissolve the outline of the Jesus circle. See, although Jesus is God, Jesus is not the Father, nor is He the Holy Spirit. In fact, while we see the three united under one name in the Great Commission, we see them acting independently throughout Scripture. Take, for example, John 16:5-11: "“But now I go away to Him who sent Me, and none of you asks Me, ‘Where are You going?’ But because I have said these things to you, sorrow has filled your heart. Nevertheless I tell you the truth. It is to your advantage that I go away; for if I do not go away, the Helper will not come to you; but if I depart, I will send Him to you. And when He has come, He will convict the world of sin, and of righteousness, and of judgment: of sin, because they do not believe in Me; of righteousness,because I go to My Father and you see Me no more; of judgment, because the ruler of this world is judged."
If the Father, Son, and Holy Spirit are not separate personalities, statements like this do not make sense. Here, the Son says He is going to the Father, who sent the Son out, because if the Son does not go back to the Father, the Son will not send the Holy Spirit. Thus, God cannot be a monad. It is essential, in order for there to be such a hierarchy within the Godhead, that each personality must be separate.
Just as we have done with the Son, we can draw two other circles with the Father and the Holy Spirit. I typically take it for granted that even the most hardcore heretic knows that the Father is God. Even Muslims, who by nature of their false religion do not believe God can even be a Father (Qur'an 6:101), will often quote Scriptures in which the Father is identified as God, or Jesus is identified as His Son. Therefore, although the Scriptures do identify the Father as God in various ways, I do not feel the need to extend this article by demonstrating the Deity of the Father.
The Holy Spirit, on the other hand, is less commonly known to be God. Indeed, there are a vast number of anti-Trinitarian heresies regarding the Holy Spirit. Some say He is just another name for the Father. Some say He is just God's "active force". There are even those who will simply say He is a metaphor. Ultimately, however, the Holy Spirit is a conscious entity who is identified as being separate from the Father and the Son (as established above), and yet, is also identified as God.
This is both implicit and explicit. To begin with, the Holy Spirit can be blasphemed. "“And anyone who speaks a word against the Son of Man, it will be forgiven him; but to him who blasphemes against the Holy Spirit, it will not be forgiven." (Luke 12:10). Note that the Holy Spirit is not only separated from Christ here, but to blaspheme Him in the manner of these particular Jews is also more severe. Now, what is blasphemy? Blasphemy is a sin in which God is somehow reproached. It is an assault on His identity. You can blaspheme by denying His existence, claiming His identity, insulting Him, impugning His character, or various other ways. What you cannot do is blaspheme someone who is not God. Yet, here, the Holy Spirit is quite severely blasphemed, as His works are attributed to Satan.
A more explicit example of the Holy Spirit being identified as God can be seen in the beginning of Acts 5: "But a certain man named Ananias, with Sapphira his wife, sold a possession. And he kept back part of the proceeds, his wife also being aware of it, and brought a certain part and laid it at the apostles’ feet. But Peter said, “Ananias, why has Satan filled your heart to lie to the Holy Spirit and keep back part of the price of the land for yourself? While it remained, was it not your own? And after it was sold, was it not in your own control? Why have you conceived this thing in your heart? You have not lied to men but to God.”" (v1-4).
With all this in mind, what we see is that the Father is God, the Son is God, and the Holy Spirit is God. We therefore have a choice. We could, though we would be making a major, foundation-wrecking error, simply deny Scriptures which clearly identify any divine person as divine. It's erroneous, but it is at least consistent. We could also deny any Scripture that says there is only one God. But the most logical approach is to take all 4 of our circles - "What we know about God", "what we know about the Father", "what we know about the Son", and "what we know about the Holy Spirit" - and use Monotheistic verses as a magnet with which to pull the Father, the Son, and the Holy Spirit, into the God circle.
But what does all of this mean? Put simply, it means the heretics are wrong, both in their denial and their understanding of the Trinity! Heretics almost always assault the Trinity as a man-made, polytheistic doctrine. Yet, in this article, we have shown that it is, in fact, a monotheistic doctrine, even if you do not believe it is true, and it is also a Biblical doctrine.
The primary premise of the doctrine of the Trinity is that there is one God. If there are 3 Gods, the Trinity is false. But there is one God. According to the Bible, however, three separate personalities are identified as God. If there is only one God, yet there are 3 personalities legitimately identified as God, then God must be Triune. The Trinity, therefore, is a Biblical doctrine. But worryingly for the heretics, it is also an essential one.
It is not essential in the sense that one necessarily has to know it to be saved. In fact, you can be saved without having ever even heard of the Holy Spirit. However, just as no man comes to the Father but through Christ, yet even the prophets of God, such as Moses, did not know His name, so also is ignorance the only excuse for being saved apart from the Trinity. Had the resurrection occurred during David's reign, David, who did not know Christ in reality, would have been required to accept Him. This is true of Moses, Noah, the Patriarchs, Daniel, Jonah, all the Old Testament prophets who were saved by Christ, yet not yet, in their time, knowing Him. You can be saved without knowing the doctrine of the Trinity, just as they were saved without knowing the fullness of Christ. But to reject the Trinity is to reject God, because the Trinity is God. Therefore, those who reject Him cannot be saved. Therefore, my message to anti-Trinitarians is simply that you have crossed the line of no return. You now know the Trinity, and thus have no excuse for rejecting Him. Repent of every time you have, and be saved.