Why do nativist parties employ religious rhetoric when religious attendance and affiliation is declining? What explains variation in nativist religious rhetoric? Is nativist religious rhetoric simply copying Christian Democratic rhetoric? Finally, does religious rhetoric actually work, can it influence voter behavior? This dissertation employed a mixed-methods approach to explore these questions in the context of Central European nativist parties through three types of evidence: interviews with German nativist AfD officials, an original dataset of religious references from Austrian, Croatian, Czech, German, Hungarian, Polish, Slovakian, Slovenian, and Swiss party manifestos between 1990 and 2021, and a survey experiment. This project generated four main takeaways: First, interviews with German AfD officials revealed that for nativist parties seeking to promote ethno-nationalist agendas, religious rhetoric allows them to sidestep the historical baggage of Nazism and fascism. Second, I find that distribution by type of rhetoric can be explained by the politicization of religious identities over history; politics, not religion, is the primary driver of whether and how nativist parties choose to employ religious rhetoric. Third, I demonstrate that while both Christian Democratic parties and nativist parties employ religious rhetoric, nativist parties maintain an anti-institutional, anti-elite stance through primarily negative references to Islam and vaguer affirmations in support of Christianity. Fourth, the use of a religious reference by a nativist candidate decreases support, except among nativist true-believers, suggesting that nativist parties are either targeting the party faithful or that it is an unsuccessful strategy to appeal to mainstream voters. Counterintuitively, despite framing themselves as defenders of the ``people," nativist parties use religious rhetoric to define who the "people" are not, rather than who the "people" are.