Previous literature on religion and sexual behavior has focused on narrow definitions of religiosity, including religious affiliation, religious participation, or forms of religiousness (e.g., intrinsic religiosity). Trends toward more permissive premarital sexual activity in the North American Christian-Judeo religion support the secularization hypothesis of religion, which posits an increasing gap between religious doctrine and behavior. However, the recent rise of fundamentalist and new age religious movements calls for a reexamination of the current link between religion and sexual behavior. The use of dual definitions of religiosity, including religious affiliation and dimensional subtypes, may further characterize this link. The present cross-sectional study evaluated patterns of sexual behavior in a young adult sample (N = 1302, M age = 18.77 years) in the context of the secularization hypothesis using religious affiliation and a liberal-conservative continuum of religious subtypes: paranormal belief, spirituality, intrinsic religiosity, and fundamentalism. Results indicated few affiliation differences in sexual behavior in men or women. Sexual behaviors were statistically predicted by spirituality, fundamentalism, and paranormal belief, and the endorsement of fundamentalism in particular was correlated with lower levels of female sexual behavior. The secularization hypothesis was supported by consistent levels of sexual activity across affiliations and is contradicted by the differential impact of religiosity subtypes on sexual behavior. Findings suggested that the use of religious subtypes to evaluate religious differences, rather than solely affiliation, may yield useful insights into the link between religion and sexual behavior.