Theologian Joel Morales Cruz has striven to write an ‘ecumenical’ (p. 195) history – one that places the foundation and growth of a church into its native context – of Mexico's Iglesia de Jesús. This was a small, reformed, nationalistic Catholic movement supportive of nineteenth-century Mexican liberalism. It thus stood in opposition to the hierarchy and many others in the Catholic Church who impugned liberal legislation that stripped the clergy of its legal privileges and divested the Church of much land. Internal theological disputes, lack of government aid and a failure to consecrate a native episcopacy weakened the movement, and by 1872 the Iglesia de Jesús had formed a covenant with the Episcopal Church of the United States for guidance and financial support. In 1906 it officially became a mission branch of the Episcopal Church, and in 1995 it became an independent Church of the Anglican Communion.

Morales Cruz's ecumenical history revises much historiography on Protestantism's origins in Latin America. Traditional narratives about the advent of Latin American Protestantism in the nineteenth century focus on foreign missionaries and settlers and thus implicitly locate its beginnings outside the region. Morales Cruz, on the other hand, argues that the Iglesia de Jesús, at its inception, was a ‘proto-Protestant’ (p. 3) movement that stemmed from Mexico's multi-racial society and pluralistic religious culture. In particular, he finds many resemblances between the theology of the Iglesia de Jesús and the Enlightenment Catholicism of late eighteenth-century religious reformers like Archbishop of Mexico Francisco Antonio Lorenzana and Bishop of Puebla Francisco Fabián y Fuero. These similarities include a desire for inward piety devoid of baroque extravagance, a focus on the individual believer's relationship with God and an implicit critique of hierarchy, and a preference for national rather than Roman authority over the Church. Furthermore, the author argues that Enlightenment Catholicism was spawned out of the openness of Mexico's baroque religiosity, even though eighteenth-century reformers tried to eradicate baroque practices. In short, Morales Cruz asserts that the Iglesia de Jesús was an internal development within a long history of Mexican society and religion. Moreover, it grew vigorously for a short while, but lack of clear leadership and personality conflicts splintered the movement's unity. Only well after its birth and because of growing pains did the Iglesia de Jesús join the Episcopal Church.

The desire to place the Iglesia de Jesús into an extended social and religious context shapes Morales Cruz's methodology and the book's layout. The book is largely a synthesis of secondary sources; the author uses only a handful of primary documents, mostly letters from a few priests in the Iglesia de Jesús that are now housed in the Episcopal Church Archives in Austin, Texas. The first two-thirds of the volume provide a summary of Mexican society and Catholicism from the conquest through the early republic. There are chapters on colonial Church–state relations, baroque Catholicism, Enlightenment Catholicism, and Church–state relations after independence. Only the last chapter (excluding the conclusion) deals with the Iglesia de Jesús. Even this chapter relies heavily on secondary literature.

Although Morales Cruz presents plausible arguments, his methodology renders his conclusions merely speculative. The general overview he offers of Mexican religion and the Iglesia de Jesús is simply not thorough or nuanced enough to sustain his analysis. Much about the origins, theology, growth, internal functioning and transformation of the Iglesia de Jesús remains to be studied. Beyond these institutional issues, we certainly need to know more about the Iglesia de Jesús’ membership and the motives of its congregants. Who were the lay members of the Iglesia? Why did they abandon the Catholic Church to join the reformed movement? How did their politics and piety compare to those of their Catholic compatriots? What did they think about the growing relationship between their Church and the US Episcopal Church? The answers to these questions will require delving deep into the primary sources.

Religious studies scholars unfamiliar with Latin America will likely appreciate the synthesis Morales Cruz has provided; Latin American specialists will find little new in it.