Several scholars suggest that religion is on the rise in party competition due to the upswing of radical right parties presenting themselves as defender of Christianity against a Muslim threat. The lack of comparative and longitudinal studies calls for a systematic investigation of parties’ religious references in order to know whether religion indeed is on the rise in party politics. Conducting a partially computer-based quantitative content analysis of 71 election manifestos in five countries since the 1980s, we provide empirical evidence that religion is recently gaining salience in party competition. The study reveals that we are experiencing the evolution of a new religious cleavage originating from the exclusion of Islam and resulting in an emphasis on Christian roots and values and in a strategic use of secular arguments by the radical right. The findings further suggest that mainstream parties responded to these religious discourses by incorporating religious elements in their own election manifestos.