For there are some who deny that a commonwealth is daily framed which, neglecting the political system of Moses, is ruled by the common laws of nations. Let other men consider our perilous and seditious this notion is.; it will be enough for me to have proved it false and foolish. We must bear in mind that common division of the whole law of God, administered by Moses, into moral, ceremonial, and judicial laws. And we must consider each of these parts, that we may understand what there is in them that pertains to us, and what does not. In the meantime, let no one be concerned over the small point that ceremonial and judicial laws also pertain to morals. For the ancient writers who taught this division, although they were not ignorant that these two latter parts had some bearing upon morals, still, because these could be changed or abrogated while morals remained untouched, did not call the, moral laws. They applied this name especially to the first part, without which the true holiness of morals cannot stand. The moral law (to begin first with it) is contained under two heads, one of which simply commands us to worship God with pure faith and piety; the other, to embrace men with sincere affection. Accordingly, it is the true and eternal rule of righteousness, prescribed for men of all nations and times, who wish to conform their lives to God’s will. For it is his eternal and unchangeable will that he himself indeed be worshipped by us all, and that we love one another. The ceremonial law was the tutelage of the Jews, with which it seemed good to the Lord to train this people, as it were, in their childhood, until the fullness of time should come…in order that he might fully manifest his wisdom to the nations, and show the truth of these things which then were foreshadowed in figures. The judicial law, given to them for civil government, imparted definite formulas of equity and justice, by which they might live together blamelessly and peaceably. Those ceremonial practices indeed properly belonged to the doctrine of piety (inasmuch as they kept the church of the Jews in service and reverence to God) and yet could be distinguished from piety itself. In like manner, the form of their judicial laws (although it had no other intent than how best to preserve that very love which is enjoined by God’s eternal law) had something distinct from the precept of love.

—John Calvin, Institutes of the Christian Religion, 1536 Edition, trans. F. L. Battles (Grand Rapids: Eerdmans, 1975), 6.48