Connecting ‘vertical’ and ‘horizontal’ dimensions of populism, Lukas Meyer explains why Brexit undermines the traditional distinction between political left and right. Regarding the referendum, the vertical dimension became visible in the idea of a Eurocratic conspiracy, whereas the horizontal dimension became visible in the anti-migrant sentiment of many Brexiteers. Therefore, the main arguments for Brexit were populist. When examining the Christian debate, however, the arguments took a specific turn. All Christian Brexiteers were convinced that there could and should be a great restitution of the British nation. As a reply to this kind of Christian populism, Meyer proposes a re-launch of the Conciliar Process with a closer reference to the European Union. The lack of a theology of Europe was the main issue. By identifying justice, peace, and the integrity of creation as political guidelines, European unity could be conceptualized theologically.