Much power is granted by the Reformed Churches and orthodox writers to the political magistrate in reference to church affairs. Take it in these particulars.

1. A defensive protecting, patronizing power to the church and all the members thereof. “Kings shall be thy nursing fathers” (cf. Isa. 49:23); “The magistrate is the minister of God for good to well-doers, as well as the avenger, executing wrath upon evil-doers; a terror not to good works, but to the evil (Rom. 13:3-4). He is called “an heir, or, possessor of restraint, to put men to shame” (Judg. 18:7). and as [such] the church ought to “pray for kings and all in authority” (so consequently all in authority should endeavor it) tha the church and people of God should lead a quiet and peaceable life (under the wing of their protection) in all godliness and honesty (1 Tim. 2:2). And this is evident from the end and scope of these prayers here prescribed by interpreters unanimously agree. And hereupon are those promises to the church: “The sons of strangers shall build up they walls, and their kings shall minister unto thee” (Isa. 60:10); and “thou shall suck the breast of kings” (Isa. 60:16). Now, this nursing protecting care of magistrates toward the church puts forth itself in these or like acts, viz., he: (1) Removes all external impediments of true religion, worship of God, etc., by his civil power, whether persons or things, whether persecution, profaneness, heresy, idolatry, superstition, etc., that truth and godliness may purely flourish; as did Jehoshaphat, Asa, Hezekiah, Josiah. And hereupon it is that God so oft condemns the not removing and demolishing of high-places and monuments of idolatry (1 Kings 15:14 with 2 Chron. 15:17; 1 Kings 22:44; 2 Kings 12:3); and highly commends the contrary in Asa (2 Chron. 15:8, 16), in Jehoshaphat (2 Chron. 17:3-4, 6-10), in Hezekiah (2 Chron. 31:1; 2 Kings 18:4), in Manassas (2 Chron. 33:15), in Josiah (2 Kings 23:8, 13, 19, 20, 24), whereupon the Holy Ghost gives him that superlative commendations above all kings before and after him (vs. 25). (2) [Patronizes], countenances, advances, encourages by his authority and example the public exercise of all God’s ordinances and duties of religion within his dominions, whether in matter of divine worship, discipline, and government — maintaining for the church the fullness of spiritual liberties and privileges communicated to her from Christ: as did ASa (2 Chron.15:9-16); Jehoshaphat (2 Chron. 20:7-9); Hezekiah (2 Chron. 29-31 and throughout); Josiah (2 Chron. 34 and 35). and to this end God prescribed in the Law that the king should still have a copy of the law of God by him, therein to read continually (Deut. 17:18-20), because he was to be not only a practicer, but also a protector thereof, custos tabularum, i.e., a keeper of both tables. (3) Supplies the church with all external necessities, provisions, means, and worldly helps in matters of religion: as, convenient public places to worship in, sufficient maintenance fo ministers, as the Scripture requires (1 Tim. 5:17-18; 1 Cor. 9:6-15; Gal. 6:6), schools and colleges for promoting of literature, as nurseries to the prophets, etc., together with the peaceable and effectual enjoyment of all these . . . or worldly utensils, for comfortable carrying on of all public ordinances of Christ. Thus, David prepared materials, but Solomon built the Temple (1 Chron. 22); Hezekiah caused the vessels of the Temple to brought in (2 Chron. 29:19) and commanded the people that dwelt in Jerusalem to give the portion of the Priests and the Levites that they might be encouraged in the Law of the Lord. And Hezekiah himself and his princes came, and saw it performed (2 Chron. 31:4, etc.); Josiah repaired the House of God (2 Chron. 34). Nor need the magistrate think scorn — but rather count it his honor — to be an earthly protector of the church, which is the body of Christ, the Lamb’s wife, for redeeming of which Christ died, and for gathering and perfecting the very world is continued.
2. A diatactic ordering regulating power is also allowed to the magistrate about ecclesiastical matters in a political way. So that he warrantably: (1) Reforms the church when corrupted in divine worship, discipline, or government: as did Moses (Exod. 32); Joshua (Joshua 24); Asa (2 Chron. 15); Jehoshaphat (2 Chron. 17); Hezekiah (2 Kings 18); Josiah (2 Kings 23; 2 Chron. 34). (2) Convenes or convocates synods and councils made up of ecclesiastical persons, to consult, advise, and conclude determinatively according to the Word, how the church is to be reformed and refined from corruptions, and how to be guided and governed when reformed, etc. For: [1] Pious magistrates under the Old Testament called the church together, convened councils: David, about bringing back the Ark (1 Chron. 13:1-2) and another council when he was old (1 Chron. 23:1); Solomon (1 Kings 8:1); Hezekiah (2 Chron. 29:4); and Josiah (2 Kings 23:1-2). [2] All ought to be subject ot superior powers, who ought to procure the public peace and prosperity of the church (Rom. 13:1-2, etc.; 1 Pet. 2:13, etc., 17; 1 tim. 2:2). Therefore, superior powers may convocate councils. [3] Christian magistrates called the four general councils: Constantine, the first Nicene Council; Theodosius Senior, the first Council of Constantinople; Theodosius junior, the first Ephesian Council; Marian Emperor, the Chalcedon Council. And [4] Hereunto antiquity subscribes [as Dr. Whitaker observes].
3. Backs the laws of God with his secular authority, as custos t, enjoining and commanding, under civil penalties, all under his dominion strictly and inviolably to observe the same: as, Josiah made all that were present in Israel to swear to serve the Lord their God (2 Chron. 34:33); Nehemiah made the Sabbath to be sanctified, and strange wives to be put away (Neh. 12:13, etc.); indeed, Nebuchadnezzar an heathen king decreed that whosoever should speak amiss of the God of Shadrach, etc., should be cut in pieces, and their bones made a dung-hill (Dan. 3:28-29); and Darius decreed, “That in every dominion of his kingdom, men tremble and fear before the God of Daniel,” etc. (Dan. 6:26-27). And as he strengthens the laws and ordinances of God by his civil authority, so he ratifies and establishes within his dominions the just and necessary decrees of the church in synods and councils (which are agreeable to God’s Word) by his civil sanction.

Jus Divinum Regiminis Ecclesiastici, 121-124.