Two Reasons Why the Trinity Matters

Let’s assume you believe the trinity is biblical. You still might wonder if it’s as important as some people claim. For example, the Athanasian Creed treats the trinity as a matter of life and death. “Whoever wishes to be saved must think thus of the trinity. And whoever rejects this faith will perish everlastingly.” 

You might read that and think, “Really? That seems like an overstatement. I mean, surely something that important would be a little easier to understand.” I suspect many who affirm the doctrine of the trinity don’t realize why it matters so much.

I also suspect that many Christians tend to think of the trinity as somewhat arbitrary—like God’s command  not to eat the fruit of the tree of knowledge. It wasn’t that the tree was intrinsically bad—it was more of a test to see whether they would trust and obey God for his own sake. In a similar way, I suspect many tend to think of the trinity as some complicated puzzle that God revealed to us just to see if we would believe him.

Finally, I’ve a hunch some Christians undervalue the trinity because they regard behavior as more important than beliefs. Church discipline is rare in our culture for any reason. But I could more easily imagine a church excommunicating someone for adultery than for denying the trinity. I mean, are we really going to kick someone out of our church simply for thinking wrong thoughts? The trinity doesn’t seem all that practical—and, of course, if it isn’t practical, how important could it be?

If any of those thought patterns describes you, then I’d like to persuade you to consider whether the Athanasian Creed might be right after all. I would argue that the Trinity is more than just a mind-bending math problem; it is married to the mystery of the gospel itself. In the words of the Catholic Catechism,

“The mystery of the Most Holy Trinity is the central mystery of Christian faith and life. It is the mystery of God in himself. It is therefore the source of all the other mysteries of faith, the light that enlightens them. It is the most fundamental and essential teaching in the “hierarchy of the truths of faith.”

Or in the words of the Second London Baptist Confession:

“[This] doctrine of the trinity is the foundation of all our communion with God, and comfortable dependence on him.”

Does it matter? Yes it matters.  Let me share with you two reasons why.


1. The Trinity matters because the gospel matters.

The Trinity isn’t some complicated distraction from the simple gospel—it’s actually part of the gospel. Now, as Fred Sanders once observed, this doesn’t mean you should begin every witnessing encounter with “God loves you, and has a wonderful trinity for you to understand.” You don’t have to unpack the trinity in every gospel presentation (although you might, especially if you’re talking to a Muslim).

Nevertheless, I would maintain that the Holy Trinity is right below the surface even in the simplest gospel presentation (and it may even poke its head up now and then).

If you don’t believe me—if you still think the trinity is just advanced theology for the experts—consider John 3:16, one of the most famous and simple gospel statements in the whole New Testament. And think carefully about what it says:

For God so loved the world that he gave his only begotten Son, that whoever believes in him should not perish, but have eternal life.

Did you ever notice that even in John 3:16 you’re already wading into trinitarian waters? Don’t get me wrong—I’m not saying that the whole doctrine is here full-blown (you’ll need the rest of John’s Gospel to get the Holy Spirit, including a few verses earlier in 3:5). But just think about all the trinity-related truths that are stated or implied in this one simple verse. I can think of at least six:

  • First, two of the three persons are explicitly mentioned: God and his only begotten Son.
  • Second, the fact that God has a Son tells us that he’s a Father. It also suggests that when Scripture speaks simply of “God,” it’s often referring specifically to the Father.
  • Third, the fact that the Father gave his Son tells us that they’re distinct persons. The Father can’t be the Son if he gave the Son.
  • Fourth, it says something about how the Father loves his Son that giving him would be the ultimate demonstration of his fatherly love.
  • Fifth, the fact that Jesus is referred to as God’s only Son suggests that there’s something unique about Jesus’s sonship. After all, Scripture teaches that God has other sons (Job. 2:1; Hebrews 2:10). In fact, John has already told us in 1:13 that when we believe in Jesus, we become God’s children. So how can he say that Jesus is God’s only Son? Answer: because while we are sons by grace, he is Son by nature. We become God’s sons by adoption and regeneration, but he doesn’t become God’s Son—he simply is God’s Son, begotten from the Father before all worlds, God from God, light from light, begotten and not made.
  • Sixth, John 3:16 tells us that this is how we receive eternal life—by the Father giving his Son. Salvation is trinitarian. The Father has an only, eternally begotten Son, and in his love for sinners he sends that Son for us. The Son of God becomes a Son of Man, so that the sons of men might become sons of God. And then, the Father and Son send their Spirit to to dwell in us so that we can experience this new life as sons (John 3:5, 7:37-39, 15:26, 16:12-15).

As Paul puts it in Galatians 4,

…when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons. And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” (Galatians 4:4-6 ESV)

As one writer has said, “The Trinity and the gospel have the same shape.” Do you begin to see why? It’s because this is how God saves us—by sending his Son and Spirit. Our salvation hangs on these two sendings. Without them, God would still be a Father, but he wouldn’t be our Father. He would still have a Son, but he wouldn’t have many sons.

The Trinity matters because the gospel matters.


2. The Trinity matters because God matters

The Trinity matters because this is who God is. It’s who he always was and would have been even if there had been no you, no me, and no heavens and earth. The question is not first and foremost, “Is this practical?” or “Will this be on the test?”  The question is “Do I want to know God?” As Fred Sanders observes,

It makes no sense to ask what the point of the Trinity is or what purpose the Trinity serves. The Trinity isn’t for anything beyond itself, because the Trinity is God. God is God in this way: God’s way of being God is to be Father, Son, and Holy Spirit simultaneously from all eternity, perfectly complete in a triune fellowship of love. If we don’t take this as our starting point, everything we say about the practical relevance of the Trinity could lead to one colossal misunderstanding: thinking of God the Trinity as a means to some other end, as if God were the Trinity in order to make himself useful.

I stress this because I think one of the reasons we Americans neglect the Trinity is because we are so pragmatic. Instead of asking “Is it true?” we’re more likely to ask “Is it useful?” “Will it help me get ahead?” “Will it make me a better spouse or parent?” Those are all good questions, but if that’s all that matters to us, then how are we any different from the pagans? Even the pagans care about those things.

The number one question is, “Do you want to know God?” Because as Jesus said, “This is eternal life: that they know you the only God and Jesus Christ whom you have sent” (John 17:3).

To know God savingly is to know him as Father, Son, and Holy Spirit, or not know him at all. Anything less is sub-Christian. The Trinity matters because God matters, even if it doesn’t strike us as practical.

And yet it is practical.

In fact, not only is it practical, it’s immediately practical. You can make it practical right now by worshipfully singing the Doxology. You can make it practical right now by praying to the Father through the Son in the power of the Holy Spirit. But whether  you do either of those things right now, one thing is certain: you live and move and have your being at the pleasure of a God who creates and sustains all things by his Son and Spirit.

The doctrine of the Trinity is practical because this is the God we worship, and the God to whom we have been joined in the bonds of gracious love. This is the God with whom we have communion and fellowship. He’s not just God–he’s God the Father, God the Son, and God the Holy Spirit.

This is the Holy Trinity. This isn’t just a doctrine; this is our life. It’s is more than just a mystery or a mind-bending math problem; this is our God,
who loved us and gave his Son for us (John 3:16)
who loved us and gave himself for us (Gal. 2:20)
who loves us and lives inside of us (Rom. 5:5).

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