Thinking about the Trinity is hard, because this conception of God is so foreign to us. We have no categories for thinking this way about God. This is true, not just because we’re intellectually limited, but because of sin.
The Triune God is holy, that is to say, he is utterly distinct from us, particularly in his being love. God is love, because God is Persons who love One Another with Divine Love. This makes God entirely self-giving, ultimately Other-oriented within himself.
God created us in his image, to be in relationships of love with him and each other. That’s the way things are supposed to be. But instead we chose self-love, and broke the world. Now we are individualistic, self-centered beings who cannot imagine true community or divine other-orientation (love). Michael Reeves says, “When I ask atheists to describe the God that they don’t believe in, they describe Satan rather than the Trinity.” We can only imagine God to be like us – maybe bigger and better, but ultimately like us. We remake God in our image. Godmust be monopersonal and self-oriented, because that’s what I’m like, and anything else is incomprehensible (because, after all, I’m the best thing I know).
So, if we’re going to know God as he truly is – a Triune God of love –he’s going to have to make himself known to us. Robert Letham says, “The whole tenor of fallen man is the pursuit of self-interest, but God actively pursues the interests of the other.” Because God loves the other, even though we have distorted his image in us by our self-love, we have not stopped him from pursuing us. The Father sent the Son to reveal God to us, to reconcile us to himself through his life and death for us. And the Father and Son sent the Spirit to us to put the very love of God right into our hearts, to make us receptive to his Word, so that we can know him as he truly is. God has not left us alone in our self-centeredness. Because God is love, he has come to us and drawn us up into his life of love, even though we were his enemies.