From this article:
My fellow Christians have argued that the state’s authority is divinely given. They cite Christ’s injunction “Render unto Caesar the things that are Caesar’s” and St. Paul’s words “The powers that be are ordained of God.” But Christ didn’t say which things — if any — belong to Caesar; his ambiguous words are far from a command to give Caesar whatever he claims. And it’s notable that Christ never told his disciples either to establish a state or to engage in politics. They were to preach the Gospel and, if rejected, to move on. He seems never to have imagined the state as something they could or should enlist on their side.
At first sight, St. Paul seems to be more positive in affirming the authority of the state. But he himself, like the other martyrs, died for defying the state, and we honor him for it; to which we may add that he was on one occasion a jailbreaker as well. Evidently the passage in Romans has been misread. It was probably written during the reign of Nero, not the most edifying of rulers; but then Paul also counseled slaves to obey their masters, and nobody construes this as an endorsement of slavery. He may have meant that the state and slavery were here for the foreseeable future, and that Christians must abide them for the sake of peace. Never does he say that either is here forever.