I like these word about the Trinity found in The Sacred Romance: Drawing Closer to the Heart of God, p. 73
"The story that is the Sacred romance begins not with God alone, the Author at his desk, but God in relationship, intimacy beyond our wildest imagination, heroic intimacy. The Trinity is at the center of the universe; perfect relationship is the heart of all reality. Think of your best moments of love or friendship or creative partnership, the best times with family or friends around the dinner table, your richest conversations, the acts of simple kindness that sometimes seem like the only things that make life worth living. Like the shimmer of sunlight on a lake, these are reflections of the love that flows among the Trinity. We long for intimacy because we are made in the image of perfect intimacy. Still, what we don't have and may never have known is often a more powerful reminder of what ought to be.
Our story begins with the hero in love. As Buechner reminds us, "God does not need the Creation in order to have something to love because within himself love happens."