The Multidimensional Religious Ideology (MRI) scale is a new 43-item measure that quantifies conservative versus liberal aspects of religious ideology. The MRI focuses on recurring features of ideology rooted in innate moral instincts while capturing salient differences in the ideological profiles of distinct groups and individuals. The MRI highlights how religious ideology differs from political ideology while maintaining a robust grounding in the social psychology of ideology generally. Featuring three major dimensions (religious beliefs, religious practices, and religious morality) and eight (...) subdimensions, the MRI is sensitive enough to generate novel insights into religious ideology across demographic groups and individual differences. The MRI is also summative, yielding a single quantitative measurement of left–right religious ideology with good scale and test–retest reliability. Analysis of 839 respondents across two studies confirmed the widespread assumption that religious ideology is a parallel construct to political ideology, emerging from similar foundations but following a distinct set of rules. The MRI shows the importance of conceptualizing ideology in ways that access the full spectrum of real-world ideological convictions—an important reminder, given the salience of religious factors for influencing ideology generally. (shrink)