The Reign of God constitutes the first detailed and systematic critical engagement with Oliver O'Donovan's political theology. It argues that O'Donovan's theological account of political authority is not tenable on the basis of exegetical and methodological problems.

The book goes on to demonstrate a way to refine O'Donovan's theology of political authority by incorporating insights from his earlier work in moral theology. This can provide a cogent basis for thinking that the Christ-event redeems the natural political authority embedded in the created order and inaugurates its new historical bene esse in the form of Christian liberalism.