According to the Reformed Church of Geneva, Germany, France, Holland, and Scotland, the relation of the state and Church is taught in the following propositions as given and sustained by Turrettin. Lec. 28, Ques. 34.
1. Various rights belong to the Christian magistrate in reference to the Church.
This authority is confined within certain limits, and is essentially different from that of pastors. These limits are thus determined, a. The magistrate cannot introduce new articles of faith, or new rites or modes of worship. b. He cannot administer the word and sacraments. c. He does not possess the power of the keys. d. He cannot prescribe to pastors the form of preaching or administration of the sacraments. e. He cannot decide on ecclesiastical affairs, or on controversies of faith, without consulting the pastors.
On the other hand, a. He ought to establish the true religion, and when established, faithfully uphold it, and if corrupted, restore and reform it. b. He should, to the utmost, protect the Church by restraining heretics and disturbers of its peace, by propagating and defending the true religion, and hindering the confession of false religions, c. Provide proper ministers, and sustain them in the administration of the word and sacraments, according to the word of God, and found schools as well for the Church as the state, d. See that ministers do their duty faithfully according to the canons of the Church and the laws of the land. e. Cause that confessions of faith and ecclesiastical constitutions, agreeable to the Scriptures, be sanctioned, and when sanctioned adhered to. f. To call ordinary and extraordinary synods, to moderate in them, and to sanction their decisions with his authority.
The question, "whether the state can rightfully force its subjects to profess the faith," is answered in the negative. The question, "whether heretics should be capitally punished," is answered in the affirmative, provided their heresy is gross and dangerous to the Church and state, and provided they are contumacious and malignant in the defense and propagation of it.
(source - C. Hodge, The Church and Its Polity - p. 114)