Confessions and the Magistrate

Steven Wedgeworth at Wedgewords has an interesting compilation of the Reformed confessions' statements on the civil magistrate (link). Those Presbyterians who follow a radicalized two kingdoms approach (contrasted with the more moderate and Scriptural form taught by the Reformers) will feel themselves at odds with what amounts to the apparent majority of the Reformed consensus, although it should be noted that they would be more comfortable (though still a bit queasy) with the shorter presentation provided in the London Baptist Confession of 1689:

Paragraph 1. God, the supreme Lord and King of all the world, has ordained civil magistrates to be under him, over the people, for his own glory and the public good; and to this end has armed them with the power of the sword, for defence and encouragement of them that do good, and for the punishment of evil doers.1
1 Rom. 13:1-4

Paragraph 2. It is lawful for Christians to accept and execute the office of a magistrate when called thereunto; in the management whereof, as they ought especially to maintain justice and peace,2 according to the wholesome laws of each kingdom and commonwealth, so for that end they may lawfully now, under the New Testament, wage war upon just and necessary occasions.3
2 2 Sam. 23:3; Ps. 82:3,4
3 Luke 3:14

Paragraph 3. Civil magistrates being set up by God for the ends aforesaid; subjection, in all lawful things commanded by them, ought to be yielded by us in the Lord, not only for wrath, but for conscience’ sake;4 and we ought to make supplications and prayers for kings and all that are in authority, that under them we may live a quiet and peaceable life, in all godliness and honesty.5
4 Rom. 13:5-7; 1 Pet. 2:17
5 1 Tim. 2:1,2

Most particularly, even the Baptists (the least "magisterial" of the Reformers) recognized that the civil magistrate's responsibility in his office is to glorify God and do what is good. Thus, there is no appeal to an abstract natural law system for governing the state - but rather the system is specifically theistic and Christian, governed by what is acceptable in God's eyes, not simply what is accepted among men.

-TurretinFan