Abstract We distinguish two streams of theory that dominate explanations of religious change: cohort-based cumulative decline theory, which emphasizes small and ongoing declines in individual religiosity accruing across generations; and political backlash theory, which emphasizes period- and identity-based changes due to the politicized meaning of religion. Notably, Muslim countries have largely been excluded from a recent wave of quantitative research on individual-level religious change, implicitly continuing an assumption that Islamic societies require different theoretical concepts. We deploy both theories to examine religious identity and behavior over multiple decades in Turkey, a Muslim-majority country with recent social conflict over religion. Utilizing age-period-cohort interaction models, our results suggest minimal evidence for a cohort-based process in Turkey, in contrast to that observed in Western countries. Rather, a political transformation—the politicization of religion through the rise of Turkey’s AKP (Justice and Development Party) and President Erdogan—is most salient to Turkish religious change. We introduce two concepts to backlash theory—identity updating and performance signaling—to show how different dimensions of individual religiosity respond to different politicized contexts. These findings extend our understanding of religious change beyond the Western context, with further implications for theorizing political backlash and cohort-based processes.