Brazil's far-right president Jair Bolsonaro is known for the catchphrase “Brasil acima de tudo, Deus acima de todos” (Brazil above everything, God above everyone). Although born and baptized a Catholic, Bolsonaro was rebaptized in 2016 by a Pentecostal pastor. Taken together, his political slogan, which marries nationalism to a generalized Christian worldview, and his multiple religiosities (perhaps tied to political ambitions) connect the interplay of both Catholicism and Protestantism broadly defined to reactionary politics. But this apparently twenty-first-century phenomenon has a long and violent history.This history is what Erika Helgen's brilliant new book explores. In it, the author begins the religious history of modern Brazil with the “Catholic Restoration” of the early twentieth century, what the author terms “a national, coordinated institutional Catholic response to the rise of religious pluralism” in the country (p. 17). The Catholic Restoration began in earnest in 1916, during Brazil's First Republic (1889–1930), when official separation between church and state allowed the Catholic Church to strengthen its institutional power. By 1930, when Getúlio Vargas came to power, the church successfully reentered politics by allying itself with his increasingly populist regime. By Vargas's authoritarian Estado Novo (1937–45), the restoration had cemented Catholic political authority but, in doing so, disavowed any other form of religiosity. As Helgen succinctly argues, “To be Brazilian was to be Catholic, and to adhere to a non-Catholic religion was to betray the traditional cultural values that formed the foundation of Brazilian national strength” (p. 16). The dirty underside to the restoration, however, was the increase in both discursive and physical anti-Protestant violence, for which most perpetrators were never punished. By exploring the connection between the discursive and the physical, Helgen shows how seemingly “spontaneous” outbursts of violence were in fact stoked by Catholic leaders' prescriptions.Helgen's intervention reframes past historiography, which has tied religious intolerance between Christian denominations in Brazil to the 1960s and 1970s, when Pentecostal churches began growing significantly in number. Moreover, by both studying the relationships between Catholicism and Protestantism and relying on an expansive definition of Protestantism that encompasses both Protestantism and Pentecostalism, the author provides the most detailed study of Christianity in modern Brazil to date. This broad Christian approach makes a methodological intervention as well. Helgen demonstrates how conversions between Catholicism and Protestantism and within Protestant denominations were not fixed events but “journeys” that could involve multiple denominational switches.The book explores religious violence in the Brazilian Northeast, a region viewed by both Catholics and Protestants as ripe for evangelization and as the country's center of popular religiosity. Although overall rates of Protestantism were lower in the region during the early twentieth century than in other areas of the country, the dramatic changes that Protestantism took in the region—shifting from a foreign-led missionary project on the coast to a Brazilian-headed movement in the rural interior—posed direct challenges to an area that Catholic leaders believed was “the traditional heart of Brazilian Catholic culture” (p. 4). Both Protestant and Catholic leaders typecast their northeastern opponents as religious fanatics and thus potentially dangerous to national unity, drawing on a long-standing national myth of impending violent religiosity tied to a more recent history of millenarian movements and a racist and classist understanding of the region as “backward.”Helgen's analysis, based on exhaustive research in a dizzying number of local religious archives, most based in the northeastern interior, shines when discussing the daily workings of parish priests, found in the parish diaries, or the individual religious experience of participating in a Catholic santa missão (saintly mission) in a drought-stricken interior town. The author brings the reader along for the spiritual ride with engaging prose and a lively pace.Religious Conflict in Brazil engages in historiographical debates beyond the religious sphere—for example, chapter 1’s exploration of the religious facet of state corporatism under Vargas. Chapter 2’s discussion of the Brazilian Northeast's racialization is part of a growing historiography on race and regionalism in Brazil, but I wanted a more explicit engagement with this literature. At times, the racial dimensions of Brazilian religiosity and religion, especially in the Northeast, remain at a surface level. For example, Helgen makes the important point that today Pentecostals perpetrate most religious violence, this time against Afro-Brazilian religions. Yet what role, if any, did Afro-Brazilian religions, many drawing from Catholic traditions, play in this history of religious pluralism?The book will be of interest to historians of modern Brazil, Latin American religions, and political history. Helgen's research methods will be a model for any historian working in lesser-known archives, particularly private ones. And the book, written with analytical precision, couldn't be more salient, as Bolsonaro's consolidation of power shows how the marrying of religion and politics continues to shape Brazilian life.