The European Union is often depicted in the international relations literature as a secular actor and a normative power, in which religion occupies a marginal place. Yet during the Ukraine crisis, many European politicians invoked Christianity, Christian civilisation, and religious values to justify their security stances, and some did so in explicitly theological terms. This article seeks to clarify this linkage and to show how religious and civilisational language is converted into security decision-making. Its central question is how France and Poland articulate their foreign and security policies through religious references. The article argues that, in the aftermath of the Ukraine crisis, religious references have become more salient in the foreign policies of both France and Poland; however, differences in their religion–state regimes and in their national political theologies generate two distinct patterns of action. In France, religion is recast in the idiom of European values and civilisation, whereas in Poland it is expressed more overtly through the lens of a Christian West confronting an Eastern threat. This study offers a comparative analysis of the period 2000–2025, examining party texts, speeches, and official documents in both countries for religious and civilisational references, and comparing these with their behaviour on the European Union’s core security issues. The findings show that, in both cases, such religious references simultaneously legitimise hard-line positions and strengthen scepticism about transferring defence competences to the EU level.