This article argues that in the European Union (EU) we can observe a process of changing attention for religion and a change in the mobilization of religion. In focusing the analysis on how religion appears in legislation texts, religion is understood in these texts as a resource that can be mobilized by different actors and in different notions. In order to understand the process of mobilization, in a first step the article illustrates the historical frameworks that are formed by national and international laws on religion, as well as their legacy. In a second step the paper discusses the process of mobilization of religion in the EU in three episodes: the first episode (1976) is marked by a lawsuit based on religious freedom and the non-discrimination concerning religion with regard to public servants. The subsequent phase is framed by the so-called "Declaration on the status of churches" (1997) and the Charter of Fundamental Rights of the EU (2000). Finally, the third episode is marked by the Treaty of Lisbon (2008), of which article 6 (TEU) and article 17 (TFEU) will be reviewed. It is shown that the attention on and the mobilization of religion has changed in the EU from an individually based mobilization to a political involvement.