This paper investigates the phenomenon of secularization and its various causes by examining the functions of religious systems and the mechanisms through which they operate. Specifically, the research is focused on the existential insecurity hypothesis proposed by Norris and Inglehart, which suggests that as societies experience higher levels of existential security, traditional religious institutions decline while secular values gain prominence. However, previous research did not take into account that different exogenous pressures lumped under existential security may affect different aspects of religious systems, obfuscating the fact that secularization may not influence religiosity in general. To investigate the relationship between various exogenous pressures and specific aspects of religious systems, we use the National Study of Youth and Religion (NSYR) dataset, which tracks the development of religiosity among participants from adolescence to young adulthood.