Christopher Beeley has provided excellent insight into the life, theology, and spirituality of Gregory of Nazianzus in Gregory of Nazianzus on the Trinity and the Knowledge of God. Beeley begins the work with a lengthy introduction that describes the debates, councils, and important figures that preceded Gregory and highlights the major achievements and disappointments of his career as a priest. He shows the many difficulties the Pro-Nicene party encountered and gives clarity as to how multiple positions were being proposed in different councils between Nicaea (325) and Constantinople (381). He also provides a helpful short biography of the basic stages of Gregory’s life that helps the reader understand Gregory’s relationship to significant figures and events. The popular paradigm that presents the Nicene party as unified and the clear victor is presented as false, as is the notion that the Cappadocians were united in a theological agenda with the same theological formula.

Beeley’s next chapter focuses on two major themes in Gregory’s writing—purification and illumination—that earned him the title “The Theologian of the East.” Beeley skillfully communicates the spirit of worship that marked Gregory’s writings. An example of this spirit is the doctrine of purification based on Matt 5:8. If one is going to approach the infinitely pure God, one must purify himself. The more pure the worshipper, the better vision he has of the one he is worshipping who is perfectly pure.

In the next three chapters Beeley continues to show how Gregory’s doctrine of God affected his ministry and understanding of life. The role of the incarnation and its implications in the doctrine of deification as well as Christ’s role in sanctification serve as excellent examples of Gregory the pastoral theologian. These doctrines are often misunderstood, but Beeley shows how Gregory clearly keeps the Creator-creature distinction while exegeting texts that speak of deification. Gregory’s strong position on the full deity of the Spirit is also well described in light of the controversy that led up to Constantinople.

Beeley’s description of the most difficult aspect of Gregory’s doctrine of the Trinity, the role of the monarchy of the Father, will be a lasting contribution to studies of the doctrine of the Trinity and Patristic studies generally. The emphasis that Gregory puts on the Father’s being the source of deity and the cause of the Son and Spirit is difficult to understand in light of the traditional confession of one essence, three hypostases. Beeley explains that the Father’s being the source was used by Gregory to argue for the unity of the Godhead because the Son and the Spirit must be like him and work with him. Gregory avoided Arianism because he did not believe that causation or begotteness takes place in time or with regard to a physical substance. Gregory’s ability to maintain an emphasis upon unity and distinction was made clear as was his genius as an exegete and theologian in articulating his confession of the Trinity.

The final chapter describes Gregory’s pastoral ministry. This aspect of “The Theologian” is too often overlooked since he produced multiple works on the pastoral ministry that influenced prominent pastors such as John of Chrysostom, Ambrose, Gregory the Great, and possibly Augustine. He emphasizes the role and character of the pastor so that the virtue, purity, and obligation to draw the church closer to God are the primary marks of a good pastor. This chapter coupled with chapter one’s discussion of purification and illumination will be the most beneficial for pastors as they see a model of pastoral spirituality that is uncommon today.

The final chapter compares Gregory to other Fathers of the third and fourth centuries. This helpful chapter aids the reader in seeing who influenced Gregory and, more importantly, it clarifies great differences among the Cappadocians. The one Father who was missing in the comparison was Augustine, whom Beeley stated throughout the treatise stands as Gregory’s equal in the West.

Beeley was able to communicate the spirit of Gregory and the emphasis of his writings so that the reader appreciates the greatness of his pastoral and theological ministry. He was able to capture Gregory’s style, complicated thoughts, spirit of worship, and skill in exegesis. This is no small task when one considers the complicated personality and multifaceted ministry of Gregory and the fact that Gregory did not produce a major work that summarizes his thoughts. Beeley’s theological work complements the biography of John Anthony McGuckin well (St. Gregory of Nazianius: An Intellectual Biography [Crestwood, NY: St. Vladimir’s Seminary Press, 2001]). Beeley’s work should give the reader a desire to read Gregory himself to experience the elegance of his orations, the difficulties of his personality, and the great depths of his theology and spirituality. Students of theology and history will appreciate the clear portrayal of Gregory the theologian and priest and the doctrine to which he devoted the most attention: the Trinity.