Romans 13:3-4

‘Do what is good,

And you will have praise from the same,

For he is a minister of God to you for good.

But if you do what is evil,

Be afraid, for he bears not the sword in vain,

For he is a minister of God, an avenger for wrath to him who does evil.'

In a balanced sentence Paul takes up what he said in Romans 13:3 a and its contrast between someone doing good and doing evil. Those who do good will have praise from the one in authority, because he is a servant of God to them for good. But those who do evil have reason to be afraid, for he holds the sword of authority, (or possibly controls the executioner's sword), and while he is a servant of God, it is in order to be an avenger for wrath to him who does evil. In other words he acts on behalf of the wrath of God and the wrath of the state. Again Paul is assuming a governing authority which is genuinely aiming to maintain justice.

Note the parallel contrasts:

· ‘Do what is good -- but (on the other hand) if you do what is evil.'

· ‘You will have praise from him -- be afraid because of his sword.'

· ‘A minister of God for good -- a minister of God as an avenger for wrath.'