Adam Clarke's Commentary on the Bible

Verse 6 (Romans 13:6)

For this cause pay ye tribute also - Because civil government is an order of God, and the ministers of state must be at considerable expense in providing for the safety and defense of the community, it is necessary that those in whose behalf these expenses are incurred should defray that expense; and hence nothing can be more reasonable than an impartial and moderate taxation, by which the expenses of the state may be defrayed, and the various officers, whether civil or military, who are employed for the service of the public, be adequately remunerated. All this is just and right, but there is no insinuation in the apostle's words in behalf of an extravagant and oppressive taxation, for the support of unprincipled and unnecessary wars; or the pensioning of corrupt or useless men. The taxes are to be paid for the support of those who are God's ministers - the necessary civil officers, from the king downwards, who are attending Continually on this very thing. And let the reader observe, that by God's ministers are not meant here the ministers of religion, but the civil officers in all departments of the state.

- Adam Clarke's Commentary on the Bible