The prevalence of religious beliefs and practices is puzzling from an evolutionary perspective, but previous research has suggested that religious traditions may provide cooperative benefits and improve well-being. Seemingly in contrast to this claim are worldwide secularization trends in which people disaffiliate from religions and abandon belief in God. Theorists have suggested that diminished pressures on cooperation and well-being no longer motivate individuals to seek religious benefits and pay the associated participation costs. We investigate this claim using the National Study of Youth and Religion dataset, which tracks the development of religiosity among US Christians from adolescence to young adulthood (n = 3,370). Using a lagged panel design, we found that material security in Wave 1 (early adolescence) predicts a decrease in belief in God in Wave 4 (young adulthood), although this association is rather small. This result provides support for the hypothesis that participation in religious traditions is associated with living in an insecure socio-ecology, where religious systems may still confer benefits on their members; yet it is not the only driver of secularization. We conclude with a call for further research using more nuanced measures and larger sample sizes to provide deeper insights into the potentially adaptive nature of cultural systems.