Résumé : The Belgian consociational model as it was instituted in the early 20th century was built along the denominational cleavage. It opposed three pillars: a catholic one, a socialist one and a (smaller) liberal one. The religious difference was not only observable in the political goals of each pillar, but also in the background and attitudes of their members. Catholics were hardly present in either the socialist and liberal organizations. Non-catholics were very rare within catholic organizations. Voting behaviours confirmed the religious base of Belgian politics and society. From the 1960s onwards, the picture changed a lot. The ongoing process of secularization has reduced the religious division among citizens and has affected pillar organizations from parties to trade unions. Yet, not very much has been said on the consequences of this evolution. Scholars hypothesised a “secularisation of the minds”, while noting that pillar organisations remained very strong. Nevertheless, few empirical studies demonstrate whether or not the religious division is in practice no longer decisive in shaping the belongings and attitudes of Belgian citizens. In this paper we aim at studying more accurately the salience of the religious cleavage in nowadays Belgium in two directions. First, electoral behaviours are studied to determine whether religion remains a decisive variable (with a new perspective of voting behaviours of Muslims). Second, party membership is analysed in order to verify whether contemporary Belgian parties remain or not religious- and pillar-based parties. This empirical evidence will help in determining whether Belgium faces a “believing without belonging” or a “belonging without believing” phenomena.