Experiencing the Trinity by Darrell W Johnson (2002) is a good, basic introduction to the doctrine of the Trinity. Composed of five chapters over 111 pages, this book is a very quick, accessible read. Johnson's five chapters are:
1) Finding the Trinity
2) Understanding the Trinity
3) Joining the Trinity
4) Entering the Trinity
5) Experiencing the Trinity.
The first chapter was essentially a biblical defense of the doctrine of the Trinity. Johnson provided several biblical references to support the notion of the Trinity even though the word does not appear in the Bible. Frankly, though this chapter is important for establishing the groundwork, I did not find it particularly engaging. However, as the book continued, I became more and more drawn in. He opened chapter 2 with these two sentences, "'At the center of the universe is a relationship.' That is the most fundamental truth I know." He then proceeds to shows the ways we have misunderstood this mystery (e.g., tri-theism, modalism) and what the consequences will be if we get it right.
In chapter 3, we are exposed to what for Johnson is an absolutely essential thought, one he retrieved from the writings of Thomas Torrance. In his book on the Trinity, Torrance wrote, "God draws near to us in such a way as to draw us near to himself within the circle of his knowing himself." Several times throughout the book, Johnson repeated this phrase, reminding the reader how, next to the Bible, it may be the most important thing he has ever read. In other words we are "co-lovers with God," which has foundation rattling implications for our relationships with God, with one another, and with the world.
I particularly appreciated the seven words he chose to express "inter-Trinitarian dynamics": intimacy, joy, servanthood, purity, power, creativity, and peace. Oh that our relationships would manifest some of this!
He concludes the book with a beautiful reflection on Paul's prayer in the middle of his letter to the Ephesians. I have never looked at it in quite such a Trinitarian fashion before, but I am seeing with new eyes.