I sat down with Joshua Ralston to talk about his book Law and the Rule of God: a Christian Engagement with Shari’a (Cambridge, 2020). We discuss what lead him to this work, why discussions of law in Islam are missing in political theology (and why they matter), the problems of Protestant antinomianism, comparative theology and how recognising different conceptions of the law and its purpose assist interfaith work, and his account of public law as a provisional and indirect witness to the divine rule of justice