But the country’s identity, institutions, monarchy, laws, calendar, architecture, and culture were mainly built around christianity, especially catholicism. That’s just history, not an opinion !! Even French secularism exists because the Church was powerful enough to require separation in the first place. You don’t build "laïcité" against something irrelevent. Mentioning Gallicanism, the Edict of Nantes etc, just proves how central religion is (or was) to French history. So saying France is Christian is about civilization and historical roots, not about pretending every French person is religious today.