“No government can be happily established unless piety is the first concern; and that those laws are preposterous which neglect God’s right and provide only for men…it is fitting that [magistrates] should labor to protect and assert the honor of him whose representatives they are, and by whose grace they govern…As if God appointed rulers in his name to decide earthly controversies but overlooked what was of far greater importance – that he himself should be purely worshiped according to the prescription of the law…
“Princes themselves will in turn remember that their revenues are not so much their private chests as the treasuries of the entire people, which cannot be squandered or despoiled without manifest injustice. Or rather, that these are almost the very blood of the people, which it would be the harshest inhumanity not to spare. Moreover, let them consider that their imposts and levies, and other kinds of tributes are nothing but supports of public necessity; but that to impose them upon the common folk without cause is tyrannical extortion.
“These considerations do not encourage princes to waste and expensive luxury, as there is surely no need to add fuel to their cupidity, already to much kindled of itself. But as it is very necessary that, whatever they venture, they should venture with a pure conscience before God, they must be taught how much is lawful for them, that they may not in impious self-confidence come under God’s displeasure.”
-John Calvin in the Institutes, sections 4.20.9 and 4.20.13 on “Concern for both Tables of the Law” and “Concerning the right of the government to levy tribute”