Richard Lennan aptly deploys the agricultural metaphors of “seed” and “tilling” to emphasize that the church, planted by God, is intended to grow and change in history. This ecclesial development requires continual discernment or, as Lennan describes it, attentive “tilling” that nurtures healthy growth through unceasing efforts to respond to the guidance of the Holy Spirit. Only thus can the church be the sacrament in history of the awaited fullness of God's reign.

The need for such tilling should not be a controversial point, though, unfortunately, it is. A key contribution of this book is its thoroughly theological explanation for why ecclesial change is both necessary and contentious. To be apostolic is a task requiring that the church maintain the tradition inherited from the past in ways appropriate to new circumstances. However, there is and can be no blueprint guaranteeing that the church will achieve the proper balance that avoids both the hegemony of the past stifling the church's growth (perhaps even to the point of killing the church!), on the one hand, and the embrace of newness severing the church from its roots, on the other hand. Instead of seeking certainty, the faithful must attend to the Holy Spirit's ongoing work of interweaving past, present, and future because this is the proper basis for discerning the ecclesial change needed in each historical moment.

The argument of this book unfolds in six chapters through which Lennan develops his richly theological account of the church as an event of grace symbolizing God's reign. Lennan emphasizes that the church is a pilgrim community that must engage an also graced world with creativity and fidelity, while nevertheless remaining oriented to God's future. Developing each of these aspects of the church in detail and through dialogue with much of mainstream Catholic theology of the past one hundred years, Lennan's work here demonstrates the extent to which ecclesiology is intertwined with all other branches of theology. His comprehensive argument engages especially, but not only, doctrines of creation, revelation, providence, and the Trinity. Karl Rahner's work on grace and freedom is particularly prominent in Lennan's foundational argument that the church, constituted by grace, is also marked by fallible human responses—and often resistance—to that grace. Hence, the church in every era is “tillable” and must be tilled through communal discernment of the whole church, laity and clergy, as the church strives to conform better to its call. Although Lennan discusses synodality only briefly, it would not be inaccurate to say that this entire book is a defense of synods as crucial for the life of the church.

What is perhaps most refreshing about Lennan's approach is his rigorous adherence to a “both-and” rather than an “either-or” sensibility. He continually reminds his readers that the church is constituted by God's grace and by human (often sinful) freedom, that the faithful live by faith and by hope, that proper discernment needs the input of both laity and clergy, and (especially) that ecclesial fidelity requires tradition and innovation. This both-and approach results from Lennan's profoundly nuanced theological reasoning, but is also a thoroughly practical path toward overcoming the polarized divisions in the church today. As Lennan repeatedly demonstrates, most of the major positions in the church have some important, if partial, truth that ought to be recognized but also completed by other partial truths.

A further notable contribution of this book is its attention to the role of hope in this future-oriented church. Hope in God's future should inspire faithful tilling within the church because no form of the church in history can embody the fullness of God's reign. Hope in God's future also should inspire faithful engagement with the world because, no matter how dark things are, God is greater than all of the powers of evil. In a world where there are so many reasons to despair of the future, Lennan reminds his readers that the church has the crucial task of being a community of hope in this so often hopeless world.

This book provides a carefully argued, deeply inspiring, and badly needed vision of the church's nature and mission. Given the breadth and depth of its theological engagement, this book would be an excellent foundational text for any graduate or seminary class in ecclesiology. It is so clearly written that it should be accessible to advanced undergraduates and to educated laity who are theologically inclined. I heartily recommend it to anyone who wants to understand better what it means to be called to discipleship in and through the church today.