Robert Letham makes a good point in his article "The Trinity---Yesterday, Today, and the Future" that if a student or minister (or a scholar, for that matter) invests all of his thinking and devotion into the last 30 or so years in controversies over the Trinity, he's liable to be confused, imbalanced, or worse, heretical! It's best, he says, to remind ourselves of how the church has always thought about the Trinity. Always having a finger in history guards against being a single-issue Christian and provides a fresh voice for pressing controversies.
I remember having lunch with an old professor when he mentioned the danger of arrogance in theological studies. It shows up everywhere, he said. He went on to say that ignoring theology all together doesn't help either. The Bible never tells us ignorance is the remedy for pride. He suggested that whatever field you're in, whether biblical, theological, or historical studies, always maintain a robust doctrine of God. He said it guards against two forms of pride. It consistently reminds us of how small we are. And it reminds us that we need help from more thoughtful and holier men and women and stops us short of fearing authority and snubbing Christians whose shoulders we should be standing on.
Mindful of this challenge, I asked theologians Fred Sanders and Kevin Vanhoozer to provide an annotated list of suggested books on the doctrine of God. Their lists contain a fairly wide range of difficulty, from popular to technical. They are good suggestions---enough to keep you humble and hungry for God.
Fred Sanders, professor of theology in the Torrey Honors Institute at Biola University
Anselm, Monologion (circa 1070) --- Less famous than his Proslogion (with its ontological proof) or his Why God Became Man (with its satisfaction account of the atonement), the Monologion is Anselm's calm and concise doctrine of God the Perfect Being. Think of it as what Augustine would have written if he'd had a more philosophical way of speaking: "There is a certain nature or substance or essence who through himself is good and great and through himself is what he is . . . "
Frederick Faber, The Creator and the Creature (1856) --- Faber sketches, in prose that verges on being actually too gorgeous, both "what it is to be a creature" and "what it is to have a creator." This book is kind of a spirituality of createdness, and succeeds better than any other book I know at showing the implications of the mere existence of God. Faber was so Roman Catholic that he worried the pope, and this book is full of phrases like "the composition of this work has been a charity towards souls," which can be a barrier for Protestant readers; but it's a barrier well worth climbing, because Faber's gifts are so unique that there's just not a Protestant Faber out there anywhere.
Stephen Charnock, Discourses on the Existence and Attributes of God (1682) --- A book so big that reading it is almost a lifestyle choice, but there's something great on every page. Charnock follows the Puritan pattern of presenting doctrine first, followed by devotion or application. It's a method that works especially well for the doctrine of God's attributes. Another Puritan worth reading on this doctrine is Richard Baxter, whose book The Divine Life takes up a number of God's attributes, and immediately shows how deeper knowledge of that attribute transforms the believer.
A. W. Tozer, Knowledge of the Holy (1961) --- This tiny book by Tozer is the best place to start. He gets so much right, and kindles such a fire, that if you start with Tozer, you never know, you might just end up in Charnock.
Gerald Bray, The Doctrine of God (1993) --- A very stimulating book that spends a great deal of its time on the Trinity. Confident, independent-minded, but deeply formed by a comprehensive knowledge of the tradition, Bray pointed the way forward for evangelical theology in this book, especially in sections like "the priority of the personal in knowing God," which is a kind of evangelical-trinitarian manifesto.
Three single-volume treatments of the entire doctrine of God from evangelicals: John Feinberg, No One Like Him; John Frame, The Doctrine of God; and Allen Coppedge, God Who Is Triune. These books are interesting for their similarities and differences, with three fine evangelical minds attempting to answer the question, "What needs to be covered in a doctrine of God?" Feinberg's is the most explicitly philosophical, Frame's the most thematic (he is developing his "theology of lordship" here above all), and Coppedge's is self-consciously Wesleyan.
Karl Barth, Church Dogmatics II/1 (1936) --- Barth is at his best in the doctrine of the divine perfections, which he celebrates with obvious delight. Some of his writing is as thrilling as a good novel, as he introduces one perfection, then brings in another one, and weaves them together in front of the reader. The exciting dialectical interplay of God's perfections give us a glimpse of what it means to confess that the God who holds all these perfections is the living God. As always, evangelicals will want to read Barth with caution. A good guide through the hard passages is Rob Price's recent Letters of the Divine Word: The Perfections of God in Karl Barth's Church Dogmatics.
T. F. Torrance, The Christian Doctrine of God: One Being Three Persons (1996). Even from the title you can tell that Torrance is committed to asserting that the doctrine of the Trinity simply is the doctrine of God. It's not enough to have a Trinity chapter buried somewhere around page 400 of your doctrine of God; the whole doctrine ought to be explicitly about the Father, Son, and Holy Spirit throughout. This is also my recommended place to start reading Torrance if you're looking for an entry point.
Kevin J. Vanhoozer, Remythologizing Theology (2010). Vanhoozer is staging a serious intervention in the modern theological conversation about God. If you're going to venture out into academic theology, you definitely want Vanhoozer as a guide to the pitfalls and the promise of engaging that literature. He argues against a movement that he labels "voluntary kenotic-perichoretic relational panentheism," which is as bad as it sounds, and draws theology back to its task of theologically interpreting Scripture in order to confess who God is more accurately.
Kevin J. Vanhoozer, professor of systematic theology at Trinity Evangelical Divinity School
Fred Sanders, The Deep Things of God: How the Trinity Changes Everything (2010) --- This is an extremely accessible guide to the doctrine of the Trinity and its importance for all aspects of Christian faith, life, and thought. Required reading for any Christian having trouble connecting the doctrinal dots between the Trinity and the gospel. Sanders relates the identity of God as Father, Son, and Spirit to the good news that whoever believes in Jesus Christ will have eternal life with God.
William Schweitzer, God Is a Communicative Being: Divine Communicativeness and Harmony in the Theology of Jonathan Edwards (2012) --- A helpful contribution both to our understanding of America's greatest theologian (Jonathan Edwards) and to the doctrine of God. Schweitzer makes a good case for seeing "communication" as possibly the most central concept in Edwards's understanding of God in himself (i.e., the Trinity) and of God's relationship to the world. The triune God is essentially good because he is essentially disposed to communicate his knowledge, love, and joy---in other words, himself---to others.
Thomas Weinandy, Does God Suffer? (2000) --- This is a superb contribution to contemporary debates about the suffering of God. Weinandy takes on the "new orthodoxy," namely, the view that God's love implies God's suffering. He corrects caricatures of Patristic and Medieval theologians, discusses the significance of the Incarnation, and in the process makes a compelling case that the God who is impassible is more impassioned and compassionate than a God who is affected by the world.
Kevin J. Vanhoozer, Remythologizing Theology: Divine Action, Passion, and Authorship (2012) --- This book seeks to understand God's being on the basis of God's communicative action, in particular his divine speech acts. What must God be if God can do things (e.g., create, promise, justify, judge) by saying? In particular, does God "suffer" the effects of his dialogue with human beings? The proposal that emerges is a fresh restatement of classical theism (and divine impassibility) that nevertheless accounts for God's dialogical interaction with human creatures and his love for the world.
John Webster, God Without Measure: Essays in Christian Doctrine (2013) --- John Webster is one of the most important contemporary theologians producing constructive Christian doctrine in the English language. This forthcoming collection of essays treats the nature of God and God's work in providence and redemption. Each chapter is a model of "theological theology"---exemplifying faithful discipleship in the realm of reason through hard thinking and clear writing about God and the gospel on the basis of Scripture in the service of the church.