Socio-economic justice lies in the normative core of Islam. The concepts of fard-al-kifāyah and zakāh reveal its commitment to protect the poor from the arbitrariness of the rich and treat the state as an institution that maximises collective welfare. The political economy of Safavid Iran indicates that the establishment of Islam as Iran’s state religion facilitated the empire’s administrative modernisation, economic development and class formation. Contrary to conventional wisdom, I argue that religion did not only offer legitimacy grounds to the Safavid government. It also provided institutional incentives that transformed clerics into intermediaries between people and the Imperial Court, improved fiscal capacity and increased general trust toward the central government.