Brother Émile of Taizé begins his book with a personal anecdote about an encounter with Yves Congar in 1977. The story sets the tone for the entire book: Br. Émile writes with the familiarity born of extended engagement with Congar’s thought. His purpose is to recall Congar’s vision of a church that is Spirit-filled and alive, a church ready to meet the future. He first introduces Congar himself, providing in Chapter 1 a selective biography that illuminates key events and thinkers that influenced his theological work. He then examines Congar’s theological treatment of four key topics: 1) tradition; 2) reform; 3) catholicity; and 4) authority. Notably, the author does not treat Congar's theology of unity and of the laity in depth. In all, the book is a timely and useful summary of some of the essential dimensions of Congar's theology as well as a reminder of the model Congar offers of fidelity and fullness in carrying out the theological task.

In summarizing Congar’s work on tradition (Chapter 2), Br. Émile asserts that Congar’s openness to development in the life of the church was directly informed by his understanding that tradition is an open system capable of constant enrichment and essential to effecting the mission of the church. The notes struck in this chapter will be familiar to readers of Congar, yet bear repeating: tradition is the living, creative presence of the transmission of faith that characterizes the Christian community in and through history. The author relies heavily on Congar’s The Meaning of Tradition (first published in 1963), rather than his more extensive work, Tradition and traditions (1960). The later book has in its favor a clarity of structure and argument that is sometimes lost in Tradition and traditions, but it lacks the depth of historical scholarship that underpins Congar’s conclusions in his earlier text. As a result, in the summary in Faithful to the Future it may appear that Congar proposed a merely speculative theology of tradition rather than a historically-grounded analysis of the actual functioning of tradition in the life of the church.

Chapter 3 addresses Congar’s theology of reform. Here, Br. Émile works primarily from Congar’s seminal work, True and False Reform in the Church (1950) while incorporating later material, including from Congar’s Vatican II journals. The author gives relatively little consideration to Congar’s famous four conditions for reform (a single page), instead emphasizing the elements of Congar’s ecclesiology that allowed him to conceive of a non-divisive ecclesial reform. In this vein, he joins Congar’s structure-life dialectic to the “discovery of the subject” (66) prevalent in modern thought to assert the appropriateness of an expectation of reform in a church that holds actual people.

Next, in Chapter 4 – arguably the most valuable chapter in the book – Br. Émile explores Congar’s ecumenical work through the lens of his ecclesiological “sense of wholeness” (or catholicity) (81). The chapter may come as a surprise to those familiar with Congar’s ecumenical work, who might expect instead a chapter on unity. Drawing largely from Divided Christendom, Br. Émile joins Joseph Famerée and others in placing catholicity at the center of Congar’s ecclesiology (86). The space of a single chapter is not sufficient to explore Congar’s manifold interrogation of ecclesial wholeness; nonetheless, by emphasizing Congar’s concern for catholicity, Br. Émile introduces an appreciation of Congar’s sense of the Spirit-led mystery that is the church becoming ever more fully the church.

Lastly, the author considers Congar’s understanding of authority in the church. Here, Congar's historical method (missing in Chapter 2) is apparent. Working primarily from a lecture given (and later published) in 1962, “The Historical Development of Authority in the Church,” the author outlines Congar’s historical investigation into structures of ecclesial authority, followed by a brief consideration of the connections he made between authority and freedom and authority and initiative.