BOOK REVIEW: Simply Trinity: The Unmanipulated Father, Son and Spirit

We are back to start another run of blogs... lasting until April when I will take another month long break.

We start with a review of an excellent book on the Trinity.

Fred Sanders, in an excellent book on the Trinity in its own rite, states that the doctrine of the Trinity is the comprehensive truth of the Christian message. It is the all-encompassing truth that lies in the background of the gospel and every theological belief to which the Christian faith holds.

Yet the vast majority of Christians have a limited understanding of what it means to say that God exists as 1 nature in 3 persons and why this particular doctrine is so unbelievably important.

Enter, Simply Trinity: The Unmanipulated Father, Son, and Spirit by Matthew Barrett. In this book he seeks to recover the historic, orthodox doctrine of the Trinity amid what he sees as widespread modern distortions. The book’s central concern is to reaffirm the classical understanding of God as one simple, undivided being who eternally exists as Father, Son, and Holy Spirit. Barrett argues that many contemporary evangelicals—often influenced by social, functional, or economic models of the Trinity—have unwittingly adopted a view that redefines God according to human categories rather than divine revelation. His task, therefore, is both corrective and constructive; his desire, to expose how modern theology has “manipulated” the Trinity and to restate the biblical and creedal vision that defined Christian orthodoxy for centuries.

The first section of the book introduces what Barrett calls “The Great Tradition,” which includes the Nicene and pro-Nicene fathers who articulated the doctrines of divine simplicity, eternal generation, and inseparable operations. Barrett contends that these early theologians did not impose Greek philosophy onto Scripture, as is often alleged, but rather clarified biblical teaching about God’s triune identity. He emphasizes the importance of reading Scripture with the same interpretive instincts as the early church, particularly the conviction that the Father, Son, and Spirit share one undivided essence and will. This section situates the doctrine of the Trinity not as an abstract speculation but as a safeguard for the gospel itself, since it protects the confession that Jesus Christ is truly God.

In the middle chapters, Barrett examines several modern approaches that have redefined the Trinity. He discusses how the so-called “social Trinity,” influenced by figures like Jürgen Moltmann and Leonardo Boff, portrays the divine persons as a community of distinct centers of consciousness whose mutual love serves as a model for human society. While this model appeals to modern sensibilities about relationality and equality, Barrett argues that it collapses into tritheism by dividing the divine essence.

Similarly, he critiques recent evangelical proposals such as “eternal functional subordination,” which maintain that the Son is eternally subordinate in role or authority to the Father. This argument is popular for complementarians but is unnecessary for their position. But I digress. For Barrett, this view undermines the coequality and consubstantiality of the divine persons affirmed at Nicaea. Against such trends, he urges a return to the classical conviction that the Son’s obedience belongs to his incarnate mission, not to his eternal divine identity.

Barrett then turns to key classical doctrines that must be recovered to speak rightly about the Trinity. He explains divine simplicity—the idea that God is not composed of parts or attributes but is wholly and perfectly one. This doctrine safeguards the unity of the divine nature and ensures that the persons are not separate beings who cooperate but distinct relations within one divine essence. Closely connected to this is the doctrine of eternal generation, which describes the Son’s eternal relationship of origin from the Father without implying subordination or temporal sequence. The Spirit’s eternal procession is treated in similar fashion. Barrett insists that these doctrines, far from being speculative, arise from the biblical witness itself and preserve the coherence of Christian confession.

The final chapters explore the practical and doxological implications of recovering classical trinitarianism. Barrett shows how worship, prayer, and salvation are all rooted in the triune God who acts inseparably in creation and redemption. To confess the Nicene Trinity is to confess the gospel, since the same God who sent the Son and poured out the Spirit is one and undivided. The book concludes by urging readers to resist the temptation to remake God in the image of modern relational ideals and to instead embrace the mystery and majesty of the triune Lord as revealed in Scripture and confessed throughout the church’s history.

A book on the topic of the Trinity is daunting for most. Yet Barrett’s work is clear, cohesive, and readable. The Trinity is over the heads of us all, yet Barrett has made a difficult doctrine as understandable as possible.

Soli Deo Gloria