The law in general, is that part of God’s Word, which commands things just, honest, and godly, and being thus conceived, it is threefold: ceremonial, judicial, and moral.

The ceremonial law, is that part of God’s Word, which prescribed to the Jews, ceremonies, rites, and orders, to be performed in the worship of God. This law is laid down in the books of Moses, especially in Leviticus.

The judicial law, is that part of God’s Word, which prescribed ordinances for the government of the Jews’ commonwealth, and the civil punishment of offenders. The ceremonial law concerned the Jews only. The judicial law did indeed principally concern them, but yet so far forth as it tends to the establishing of the moral law, having in it common equity,* it concerns all people, in all times and places.

What the moral law is, I will describe in three points: first, it is that part of God’s Word, concerning righteousness and godliness, which was written in Adam’s mind by the gift of creation; and the remnants of it be in every man by the light of nature, in regard whereof, it binds all men.

Secondly, it commands perfect obedience, both inward in thought and affection, and outward in speech and action.

Thirdly, it binds to the curse and punishment everyone that fails in the least duty thereof, though but once, and that in thought only: ‘Cursed is every one that continueth not in all things that are written in the law to do them’ (Gal. 3:10).

The sum of the moral law is propound in the Decalogue or Ten Commandments, which many can repeat, but few do understand.

That we may further conceive aright the moral law, we must make a difference between it and the gospel, for the gospel is that part of the Word which promises righteousness and life everlasting to all that believe in Christ.

William Perkins (1558–1602), The Works of William Perkins, (1:243–44). (HT: Inwoo Lee)