An effective church with an effective ministry, in holding out the word of life, than which there is no other human good within the world or outside it, will render assistance to the political functions in societry by forwarding the social good which they exist to defend. But that is to take the very longest view of the relationship. In holding out the word of life, an effective church with an effective ministry issues the call "Repent, for the kingdom of God is at hand!" And so in the short, the medium, and even the penultimate term the presence of the church in political society can be a disturbing factor, as those who first thought Christianity worth persecuting understood quite well. It presents a counter-political moment in social existence; it restrains the thirst for judgment; it points beyond the boundaries of political identity; it undermines received traditions of representation; it utters truths that question unchallenged public doctrines. It does all these things because it represents God's kingdom, before which the authorities and powers of this world must cast down their crowns, never to pick them up again.
- Oliver O'Donovan, Ways of Judgment, 292.