The Reformed Confessions represent something of a consensus on the role of the civil magistrate. Here is a list of some of the more influential statements:
Tetrapolitan Confession-(1530 Bucer and Capito):
23- … They accordingly teach that to exercise the office of magistrate is the most sacred function that can be divinely given. Hence it has come to pass that they who exercise public power are called in the Scriptures gods… Therefore none exercise the duties of magistrate more worthily than they who of all are the most Christian and holy…
First Confession of Basel (1534 Oecolampadius):
8- God has charged governments, His servants, with the sword and with the highest external power for the protection of the good and for vengeance upon and punishment of evildoers. For this reason, every Christian governement with which we desire to be numbered, should do all in its power to see that God’s Name is hallowed among its subjects, God’s kingdom extended, and His will observed by the assiduous extirpation of crimes.
First Helvetic Confession (1536 Bullinger and others):
26- Since all governmental power is from God, its highest and principal office, if it does not want to be tyrannical, is to protect and promote the true honor of God and the proper service of God by punishing and rooting out all blasphemy, and to exercise all possible diligence to promote and to put into effect what a minister of the Church and a preacher of the Gospel teaches and sets forth from God’s Word…
Geneva Confession of 1536 (Calvin):
21- We hold the supremacy and dominion of kings and princes as also of other magistrates and officers, to be a holy thing and a good ordinance of God…
Confession of the English Congregation at Geneva (1556 Knox):
4- And besides this ecclesiastical discipline, I acknowledge to the Church a political magistrate who administers justice to every man, defending the good and punishing the evil, to whom we must render honor and obedience in all things which are not contrary to the Word of God. And as Moses, Hezekiah, Josiah, and other godly rulers purged the Church of God of superstition and idolatry, so the defence of Christ’s Church against all idolaters and heretics, as Papists, Anabaptists and such rascals or antichrist pertains to the Christian magistrates, to root out all doctrine of devils and men, such as the mass…
Scots Confession (1560):
24- … The are not only appointed for civil government but also to maintain true religion and to suppress all idolatry and superstition.
Belgic Confession (1561):
36- …And being called in this manner to contribute to the advancement of a society that is pleasing to God, the civil rulers have the task, subject to God’s law, of removing every obstacle to the preaching of the gospel and to every aspect of divine worship.
… And the government’s task is not limited to caring for and watching over the public domain but extends also to upholding the sacred ministry, with a view to removing and destroying all idolatry and false worship of the Antichrist; to promoting the kingdom of Jesus Christ; and to furthering the preaching of the gospel everywhere; to the end that God may be honored and served by everyone, as he requires in his Word.
Second Helvetic Confession (1566 Bullinger):
30- …The chief duty of the magistrate is to secure and preserve peace and public tranquility. Doubtless he will never do this more successfully than when he is truly God-fearing and religious; that is to say, when, according to the example of the most holy kings and princes of the people of the Lord, he promotes the preaching of the truth and sincere faith, roots out lies and all superstition, together with all impiety and idolatry, and defends the Church of God. We certainly teach that the care of religion belongs especially to the holy magistrate.
Thirty-Nine Articles of the Church of England (1572):
37- Where we attribute to the Queen’s Majesty the chief government, by which titles we understand the minds of some slanderous folks to be offended: we give not to our princes the ministering either of God’s word, or of Sacraments, the which thing the Injunctions also lately set forth by Elizabeth our Queen, doth most plainly testify: But that only prerogative which we see to have been given always to all godly Princes in holy Scriptures by God himself, that is, that they should rule all estates and degrees committed to their charge by God, whether they be Ecclesiastical or Temporal, and restrain with the civil sword the stubborn and evil doers.
Westminster Confession of Faith (1646):
23.3- The civil magistrate may not assume to himself the administration of the Word and sacraments, or the power of the keys of the kingdom of heaven: yet he hath authority, and it is his duty, to take order, that unity and peace be preserved in the Church, that the truth of God be kept pure and entire; that all blasphemies and heresies be suppressed; all corruptions and abuses in worship and discipline prevented or reformed; and all the ordinances of God duly settled, administered, and observed. For the better effecting whereof, he hath power to call synods, to be present at them, and to provide that whatsoever is transacted in them be according to the mind of God.