Despite the fact that churches are still important sources of social capital in the Netherlands, the ongoing secularization of Dutch society has as yet not resulted in a drop of non-religious volunteering. In order to account for this apparent paradox, panel data are used to test the hypothesis that non-religious volunteering is in part an aftereffect of the religious socialization today’s volunteers enjoyed as youths. The following research question is addressed: To what extent does a religious socialization in Christian families during adolescence, independent of individual and collective religious characteristics, determine non-religious volunteering later in life? Results show that collective religious characteristics, i.e. being active in a religious community and religious affiliation, are the most important determinants in this respect. However, next to the effects of these collective aspects, also an independent effect of a religious socialization on non-religious volunteering is found. Especially a religious socialization which is not too strict was found to be influential on adult non-religious volunteering.