This contribution responds to Saba Mahmood’s critique of secularism and uses it for theory development in liberal political philosophy. Building on the work of Rahel Jaeggi I reconstruct selected parts of Mahmood’s works as an immanent critique of secular- ism as a form of life. I argue that liberal egalitarian political philosophical approaches to religious difference should broaden the focus of social critique. Beyond – but not instead of – formal regulations such as constitutional law and religious accommodation, political philosophy needs to address what Mahmood calls “ethical sensibilities”, and informal social practices and conventions. My considerations are informed by an exploration of the refusal of some pious Muslims to shake hands with someone of the opposite sex, and controversies about this issue in Western-European countries.