This dissertation is an exploration of the religious movements within Christianity in the United States. After discussing the common strategies used in the social science literature to classify religious belonging, I develop an alternative method that leverages associational ties between religious groups and people who are not active despite their identity. I develop theory-driven classifications for people whose religious identity cannot be determined solely on their identification. The remainder of the dissertation tests whether religious movements correspond to differences in the social and political behavior of those in these religious categories. I find significant differences on demographics, religious beliefs and behaviors, and political partisanship. Significant differences are also found when the analysis is narrowed down to a specific electoral context, the election of Donald Trump in 2016. Throughout the dissertation I will compare the explanatory power of my new scheme, RELMOVE, to existing classification schemes like RELTRAD. The dissertation concludes with some final thoughts for future researchers on the usefulness of the scheme moving forward.