The only God we know is the God “for us.” For Michael L. Cook this is the all important focus of his latest book Trinitarian Christology: The Power that Sets Us Free for it affirms that the economic Trinity is the reality of the immanent Trinity and vice versa. It is his intention to develop an integrated trinitarianism with a “more robust” pneumatology and to explore its implications for a Trinitarian Christology using three key elements: evolutionary science, language about Spirit, and ecumenical (East and West) overtures.

Cook‘s starting context is the emergent universe since, he notes, theology is about the intrinsic value, dignity and integrity of each particle in the cosmos for it celebrates the divine reality that is personally and dynamically present from the beginning of creation to the end. This approach, he maintains, opens the door to a new ecumenical conversation between East and West. Assuming that the Holy Spirit is the point of contact between humanity and the Trinity, then a deeper understanding and stronger emphasis upon the action and power of the Spirit will guide us into the proper understanding of tradition as a life-giving reality.

Cook’s innovative study is based two essential issues. First, that Christology must be Trinitarian. All the events and actions in the life of Christ must be understood in light of the role of the Holy Spirit as a person. A fully developed Trinitarian understanding of the Word incarnate leads to vigorous pneumatology. Theologians have frequently called for a more integrated and well developed theology of the Holy Spirit—Cook takes the first step needed to bring it about. The second issue that this approach addresses is the need for a more ecumenical Christology. Here Cook focuses on the concerns of both the East and the West with regard to the filioque.

Seeking a higher ecumenical unity is a noble endeavor. In order to further the dialogue between East and West Cook examines the work of three contemporary theologians from the East: John Meyendorff, Vladimir Lossky and John Zizioulas. He then brings them into conversation with three contemporary theologians from the West: Jürgen Moltmann, David Coffey, and Thomas Weinandy whose work, when examined together, he suggests, offers a perspective essential to an adequate Trinitarian Christology.

Cook’s work is important because it seeks unity through a better understanding of the Trinity. Too often Christians have ignored, neglected or have never been helped to understand God as Trinity. The role of the Holy Spirit has not been adequately personalized for believers. Many are unaware of the longstanding differences between East and West and would, I suggest, struggle to understand the significance of the theological distinctions made within the traditions. In this brief but important book Cook attempts to build a bridge between East and West by means of a more developed understanding of the power of the Holy Spirit at work in the Church. It is Word and Spirit that touches hearts and it is Word and Spirit that has the power to set persons free from the limitations of discourse and practice that hinder or block agreement. Cook has taken an important step toward unity. He has listened to and allowed the Holy Spirit to speak. Cook has challenged Catholics to consider the Trinity as the model for unity both economic and immanent that can show us the way to a deeper understanding of God and unity with one another.