The best way to understand the Trinity that I always recommend is to connect the Trinity to the Gospel as directly as possible. And one of the things this means is when you begin, as a Christian, thinking about the Trinity, you actually already have all the equipment you need in your mind, and in your heart, and your experience. You’ve got all the pieces of the puzzle there. You just need to be able to see them all together to understand that what you’re thinking about is the Trinity. Here’s the reason this is important. If you think that the Trinity is something that you have not had any experience with or understanding of, you’re going to kind of go off on a hunting trip to find interesting, neat, little analogies that might kind of apply. So you’ll do, you know, an apple has a core, and the flesh of the apple, and the skin of the apple, and that’s kind of like the Trinity.
And then you’ll stop and say, “But, of course, God’s not an apple, and it’s not very much like the Trinity.” So the Trinity is kind of like water being liquid water, and ice, and steam, and then you’ll stop and say, “But, of course, that’s not what God’s like.” And people do this a lot, and it doesn’t really amount to much because they don’t really believe God is very much like any of these things.
They’re just looking for some little hook to think, “How could something that is three also be something that is one?” And it’s a pretty fruitless exercise. When I say connect the Trinity to the Gospel as directly as possible, here’s what I mean. The eternal God, who always was Father, Son, and Holy Spirit, made himself known in the central biblical act of the Father sending the Son and sending the Holy Spirit. This is the only part that’s really hard. If you ask what God is like, that is, what is the eternal triune of God like, well, what would he have been like if he had never made himself known to us? What would the being of God be? The eternal God is like the Father sending the Son and the Holy Spirit.
That is to say, when the Father sent the Son and the Father sent the Spirit, they had not been sent before. But God the Father sent them in order to show that within the very life of God, God is the Father with the Son and the Spirit eternally being from him. That’s the nature of the divine life. So the tricky part about this is, if I say that the Trinity is like the Father sending the Son and the Spirit, it doesn’t sound like I’ve explained the Trinity, but that’s because our assumption is the Trinity must be some strange, new, mysterious answer I’ve never heard before. What I really hope people get is the shock of recognizing, if I know that the Father sent the Son and the Holy Spirit, and that the Father, and the Son, and the Spirit are God, then I actually know the central most important thing about the Trinity.