Why do we believe in the Trinity?

As an evangelical Christian, Biblical Christians, born again Christians, whatever you want to call us, a lot of people are under the impression that we are required to believe in the Trinity because the Council of Nicea told us to, or something like that. That's actually not why we believe in the Trinity. We believe it because it's found in scripture. It's the result of a holistic view of scripture when you look at the Old Testament and New Testament with both eyes open and take into consideration everything that the Bible has to say on the subject. You end up with the doctrine of the Trinity.

But since there's a lot of preconceived notions and presuppositions that people have on what they think the Trinity is, let's clear those out of the way before we get to what the actual doctrine of the Trinity is. I'd like to talk first about about what the Trinity is not. What we do not mean when we say we believe in the Trinity.

First, we don't believe that Jesus is the Father and father of the Spirit and the Spirit is Jesus, and all of them are the same person. We don't believe that. That God has three different masks, plays three different parts, puts on three different costumes, or anything like that.

Second, we don't believe that there are three Gods. That the Son is one God who is separate from the Father (who was another God), who is separate from the Spirit (who was another God), then you would have tritheism. Which we don't believe, especially because the Bible emphatically teaches that there is one God and only one God.

Third, we don't believe that Jesus is subordinate, in the sense that he's a lesser God. Or that we have demigods, or different levels of gods, or anything like that. That the Father is the top God, and they out range each other, or anything like that. That's also what we don't mean we talk about the Trinity.

The actual definition of the Trinity, historically, is that the Trinity is one God who exists in three coequal, coeternal and distinct persons. Right off the bat some people are going to think that is confusing, when really the reason it's worded that way is because of what we find in scripture. We can go through these three premises to show how we arrive at the doctrine of the trinity, because a lot of people say, "the word Trinity isn't even in the Bible." We know and it is a term that was coined to put a name to concept of what the Bible teaches.

So the first premise is that there is only one God. Bible teaches us this emphatically. Deuteronomy 6:4, "Hear oh Israel, the Lord our God, the Lord is one." Or Isaiah 44:6, says, "I am the first. I am the last. Besides me there is no God." One God.

Second premise is that you find three persons in the Bible who all have these attributes of God. Attributes that only God could possess. So the Father, Son and Spirit – all of them are called God, all of them are called Creator, all of them indwell believers, all of them are omniscient (or all know), all of them are the giver of live, all of them are eternal. We could go on and on about their equality with each other.

Third, we see a distinction between these three persons and so we see that it's not God putting on three different costumes, but they are actually distinct from one another. You have Jesus at his baptism with Jesus in the water, the Spirit coming down, the Father speaking from heaven. When Jesus was praying in the garden, we see a distinction in their wills. A will would be an attribute of personhood, so you see different persons at that point. "Not my will, but let your will be done," is what Jesus says to his Father.

So with those three premises, what we end up with is a definition that sounds kinda like God is one God who exists three coequal, coeternal and distinct persons. That's how we end up with the doctrine of the Trinity. Biblically, in scripture, looking at both Testaments with both eyes open and taking everything into consideration. When we see all that, you end up with the doctrine of the Trinity.