Book 10 argues that sincere religion is still vulnerable when it has no nation, no sovereignty, and no publicly protected belonging. In that sense, faith without sovereignty remains homeless in the open.
This does not reduce salvation to politics. It means salvation is trying to become durable enough to protect a people, not only inspire isolated believers.
The image is pastorally strong because it reframes sovereignty as address and shelter. A people without protected belonging can still worship, but they remain exposed.