O.k. you preachers, gut-check time. Lift your hand if you’re not planning to preach on the Trinity this Trinity Sunday.

O.k., now lift ‘em if you didn’t know that Trinity Sunday is just a couple of weeks away, falling on June 3 this year.

So, now lift ‘em up if you’ve never preached on the Trinity during Trinity Sunday. Uh huh. Thought so.

In spite of the impression that paragraph has just given you, I’m not here to scold about this. It’s a simple fact that we don’t preach on the Trinity. We tell ourselves it’s because our people don’t want to hear it, and some truth resides in that claim. After I taught about the Trinity in a Sunday school class once, my friend Russell the cardiologist, one of the smartest people I know, said, “I don’t understand why anyone would care about this stuff; all it does it turn something that ought to be simple into something complex.”

But, let’s be honest; the main reason we don’t preach about God as Trinity is we’re not so sure we understand it all that well ourselves–or at least not well enough to say anything relevant or interesting about it. Our church history and theology professors in seminary did all they could to explain it to us, but the memory is a little fuzzy. I mean, the whole deal revolves around words like hypostasis and homoousias; what’s up with that? Two minutes into any sermon on the Trinity will find every first-grade graduate in the congregation figuring out that 1+1+1 does not equal 1, after which no one is going to listen to a word you say. Sounds like a great time to dust off that parenting series you preached at your last church, doesn’t it?

Except that we’re talking about the heart of Christian faith. We’re talking about the God who empties the divine self, takes on the form of a servant, and is crucified for us. In short, when we’re talking about the Trinity, we’re talking about Jesus.

To understand this, you have to start with the Old Testament (not the place you expected to go looking for help on preaching the Trinity, is it? Stick with me). What’s the one sin that comes up again and again in the Old Testament, that keeps getting the Israelites in trouble? Idolatry. As any Old Testament prophet can tell you, we always want a God who acts and thinks like, well, us. The temptation to remake God in our own image is as seductive as it is universal.

And what kind of God do we make for ourselves? A God of power, the Big Dog on the porch. Why do we want this kind of God? Because we wouldn’t mind having that kind of power ourselves, and since getting it hasn’t always worked out for us, we’d at least like to know that the Big Dog has our back.

The problem with this particular form of idolatry–the idolatry of power–is the same for all idolatries: sooner or later we’re going to turn them on their heads. To speak of God mostly in terms of God’s power is to imply that human power is a form of godliness, and that those with the most power are the most like God. And think about it; isn’t this what kings and despots throughout the centuries have said? “You have to listen to me because God wants order around here, and God has empowered me to make sure you stay in line.”

And this is where Jesus comes in. Because we can’t help but define the word “God” in terms of power, God decides to come show us what and who God really is, what God’s power is really about. God becomes incarnate in Jesus of Nazareth, and on the Cross paints us a picture of the very heart of God. Jesus shows us that for God, power means the power of self-sacrificial love. And because Jesus is God; the story of Jesus’s sacrifice on the Cross becomes for us the final, truest definition of the word, “God.”

This is why the early church insisted that God is Trinity. Yes, God the Father is the creator and sustainer of the universe, but to say that is not to say what is most important, most essential about God. If you ask who God really is, the answer is that God is eternally the Father of the Crucified One. If you want to know about God’s ongoing presence among us, the first thing to say is that it is the Spirit of the Risen Christ. Most important, if you want to know what all the fuss is about Jesus, it’s that in him and him alone we see and know God.

In other words, it’s all about Jesus. The doctrine of the Trinity isn’t an attempt to put God in a box, or turn something that ought to be simple into an incomprehensible mystery; it’s God’s way of telling idolaters like you and me to pipe down, pay attention, and focus on Jesus.

You don’t have to be a theologian with three PhDs in order to preach effectively on the Triune God come Trinity Sunday. In the end, all you really need is a cross and a finger to point at it.