This thesis is devoted to a major challenge – the preparation for the sacrament of marriage in postmodern societies, starting from a survey articulated on this theme, extended to the French-speaking dioceses of Belgium. We have come up with a series of observations: the often limited time devoted to preparation; the focus on the preparation of the liturgy or ceremony; the variety of reasons for requesting that the ceremony takes place in the church; social reasons, regularization of a situation, desire for a beautiful festival; the ignorance of the profound meaning of the sacrament of marriage. Without a solid preparation, one can better understand the multiplication of divorces with a large number of Christians called to live an "irregular" situation. Based on the assumption that preparation for the sacrament of marriage could give couples a chance to last while allowing them to have a connection with the Catholic Church, the thesis took into account three main parameters: socio-anthropological, theological and the reality of preparing for marriage in Belgium. With regard to the statistics of marriages and civil divorces, in view of the increasing number of cohabitations but also of the cessation of cohabitation, and finally with regard to the general decline in Catholic practice which negatively affects Catholic marriages, we sought audible explanations through socio-anthropological studies. Thus, if Jean Claude Kaufmann conducts his reflection on love, François de Singly highlights the fragility of the bonds between men. The individual in search of happiness will go through periods of solitude and pairing. François de Singly describes these periods as oscillating games. As for Zygmunt Bauman, he will ask the larger question of the links between men. These ties, which he calls "liquids", appear to be tied up in a liquid life. These sociologists were able to reveal challenges to the preparation for marriage, taking into account the postmodern context. We have therefore examined the evolution of marriage and ...