Despite the decline in religious affiliation among American adults over the past three decades, religious motivations continue to be a part of American politics. This dissertation focuses on the role of religion in two areas of American political behavior: candidate evaluations and political participation. First, I examine the impact of a candidate's use of religious language on how Christian voters evaluate them. I argue that Christian voters are attuned to religious language and that, when candidates make religious appeals, voters use these appeals as cues to determine whether a candidate is an authentic representative of their group. Using data from two original surveys with two embedded survey experiments, I test how respondents from three major Christian traditions evaluate candidates who use broad and group-specific Christian language. Results show that some Christian voters make inferences about a candidate's politics and the representation they are likely to get based on the use of Christian language. Second, I investigate how religious and political identities work together to shape voters’ political engagement. Using cross-sectional datasets covering a long period of time, I reexamine a common finding in the literature, namely, that of the positive impact of church attendance on turnout. I show how the political participation of religious Republicans and religious Democrats is differentially impacted by their religious commitment and how this varies for members of different racial and ethnic groups. Together, these findings underscore the role of religious language and religious commitments in the political behavior of American voters and contribute to a more complex understanding of the interaction between religious communities and politics.