Is there an ongoing decline in religious beliefs in the Netherlands? Using cross-sectional data from 1979 up to 2005, we focus on traditional Christian faith and belief in the supernatural; the literature suggests that they undergo diverging trends. We first describe these trends using the Social and Cultural Developments in the Netherlands surveys covering the 1979–2005 period. Explanations for the trends are formulated and tested using OLS regression models and a counterfactional simulation technique. Our findings indicate that during the 1979–2005 period both traditional Christian faith and belief in the supernatural declined, although the latter at a slower rate. Since church membership rates are continuously declining as well, belonging and believing still go hand in hand in the Netherlands. The most important explanation for both the decline in traditional Christian faith and the decline in belief in the supernatural is the slow but continuous replacement of older religious affiliated cohorts with younger nonaffiliated cohorts.