From ABC to PhD: The Holy Trinity

As we think about the Trinity and seek to grow in our understanding of this Biblical doctrine, it is always helpful to use resources of others who have spent more time thinking about the Trinity. To this end, I would like to recommend Robert Letham’s book The Holy Trinity: In Scripture, History, Theology, and Worship. It is a helpful resource that should be on the shelves of pastors and laypersons alike.

The book is divided into four sections: (1) The Biblical Foundations; (2) Historical Development; (3) Modern Discussion; and (4) Critical Issues. An obvious strength, the book covers a wide array of topics related to the Trinity. Particularly, if you are looking for a book that outlines the historical development of the articulation of the Trinity, I would recommend this book as a place to start. We are not the first to wrestle with how to understand and forumulate the doctrine of the Trinity. Church history can be a helpful guide as we ask: “how are these Biblical doctrines to be understood.”

In his first section, Letham has a helpful introduction to the Biblical arguments for the Trinity. His three basic chapters discuss the Old Testament, Jesus and the Father in the New Testament, and the Holy Spirit and Triadic patterns (where God/Father, Son/Lord, and the Holy Spirit are mentioned together). He concludes with an excursus on the book of Ephesians.

This section is a survey and a reliable guide. Letham’s pages are full of various Scripture. It is not an in-depth exegesis of each passage, nor does it need to be. Letham’s intent is not to be exhaustive but provide a solid foundation and overview, which I believe he accomplishes.

I find the most helpful portion of Letham’s work to be his discussion of the Historical development of the Trinity. He introduces the reader to early Trinitarian thought, the crisis of the Arian Controversy where Jesus’ deity was denied, then those early church Father who defended Jesus’ divinity including Athanasius and the Cappadocian Fathers. He has a short chapter on the Council of Constantinople. He devotes an entire chapter to Augustine and his articulation to Trinitarian theology. He has two chapters discussing the divergence of the Eastern and Western church, particularly over the filioque clause. His last chapter in this section surveys John Calvin’s addition to the discussion.

If one is unfamiliar with the history of the development of the doctrine of the Trinity and the meaning of important words like homousia, Letham’s work is a reliable guide and a solid introduction. His work is filled not only with quotes and citations from primary sources but he often shows how the early theologians handled Scripture. One never gets the sense that the doctrine of Trinity was built over top of Scripture. Rather the earliest theologians were seeking to unearth and define what was in the Scripture itself.

In his third section, Letham examines modern treatments of the Trinity. He discusses Karl Barth, Rahner, Moltmann, and Pannenberg.  He also discusses eastern theologians such as Bulgakov, Lossky, and Stailoae.  And finally, he has a chapter on Thomas F. Torrance. These overviews are much shorter than the discussions of more historic figures. This section is particularly helpful for a reader to get a taste of modern discussion.  Letham also balances presentation with evaluation, both strengths and criticisms. He does draw out where some have transgressed historic boundaries. He faithfully critiques unhealthy balances wherein some do not cross but are dangerously close to migrating beyond orthodox boundaries.

Finally, Letham concludes his book with a discussion of critical issues. Here, his concerns are more about the impact proper Trinitarian thinking makes for both orthodoxy and orthopraxy. He has thoughts on worship, prayer, and missions. He further discusses how we connect the Trinity to the doctrine of the incarnation and a Biblical definition of personhood.

To illustrate one of a number of convictions Letham brings in his closing section, here is what he writes on preaching in discussing Trinitarian worship:

“Chief of all, the Trinity must be preached and must shape preaching. Preaching is the high point of worship. Not only must the Trinity be preached, but all preaching must be shaped by the active recognition that the God whose word we proclaim is triune” (emphasis original, p.423).

This clearly pastoral tone marks these last chapters of the book. While the value of the Trinity is not primarily found in how we apply it, Letham nevertheless shows us that to be truly Trinitarian means the doctrine will determine certain practices in our Christian life.

Overall, this book is to be commended to you for your reading and your enjoyment.

Tim Bertolet is a graduate of Lancaster Bible College and Westminster Theological Seminary.  He earned his Ph.D. from the University of Pretoria, South Africa. He is an ordained pastor in the Bible Fellowship Church, currently serving as pastor of Faith Bible Fellowship Church in York, Pa. He is a husband and father of four daughters. You can follow him on Twitter @tim_bertolet.