It is in this opening chapter on Scripture as the foundation of all knowledge that the regulative principle appears:
The whole counsel of God concerning all things necessary for his own glory, man’s salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture: unto which nothing at any time is to be added, whether by new revelations of the Spirit, or traditions of men. Nevertheless, we acknowledge the inward illumination of the Spirit of God to be necessary for the saving understanding of such things as are revealed in the Word: and that there are some circumstances concerning the worship of God, and government of the Church, common to human actions and societies, which are to be ordered by the light of nature, and Christian prudence, according to the general rules of the Word, which are always to be observed. (WCF 1.6)
The point being made is that Scripture lays down certain principles about two particular issues (there are others): the form of church government and public worship. The same principle appears again in the chapter on worship:
The light of nature shows that there is a God, who has lordship and sovereignty over all, is good, and does good unto all, and is therefore to be feared, loved, praised, called upon, trusted in, and served, with all the heart, and with all the soul, and with all the might. But the acceptable way of worshipping the true God is instituted by Himself, and so limited by His own revealed will, that He may not be worshipped according to the imaginations and devices of men, or the suggestions of Satan, under any visible representation, or any other way not prescribed in the holy Scripture. (WCF 21.1)
The point is that Scripture (that is, God Himself, since Scripture is God’s Word) prescribes how we worship God. The word prescribe carries the idea of authority. When you go to the drugstore and you need some medicine that isn’t an “over the counter” drug, you need a prescription—it used to be a piece of paper signed by the doctor (these days it is usually done electronically).
And why did the Westminster divines (the theologians who gathered at the Westminster Assembly) think this was so important? The answer to that lies in the previous chapter of the confession, which is arguably the most important chapter in the confession and one that is set in a very special context in the seventeenth century—the chapter on liberty of conscience. It contains this vitally important statement: “God alone is Lord of the conscience and has left it free from the doctrines and commandments of men, which are, in anything, contrary to His Word; or beside it, if matters of faith, or worship” (WCF 20:2).
To insist on a certain action in worship that Scripture does not expressly command is to violate freedom of conscience. That was a vital issue in the seventeenth century. For the founding fathers of the United States of America, for example, this was a vital issue. Freedom of conscience was the only guarantee of religious liberty.
The Westminster Assembly was established in the wake of attempts on the part of the king (and the Church of England) to impose a manner of worship upon Scotland. And some of the Scots weren’t having any of it. There is the compelling story of Jenny Geddes, for example. In 1637, Charles I attempted to impose an English-style prayer book upon the nation of Scotland. The legend goes that “when Dean James Hannay began to read from it, . . . a local woman named Jenny Geddes hurled at his head the folding stool on which she had been seated, shouting, ‘Dinna say Mass in my lug!’ (‘Don’t say Mass in my ear!’).”
To impose rituals and ceremonies with religious significance that do not have express scriptural support is to violate conscience.
Where does the Bible teach the regulative principle? In more places than is commonly imagined, including the constant stipulation of the book of Exodus with respect to the building of the tabernacle that everything be done “after the pattern . . . shown you” (Ex. 25:40). Add to this the judgment pronounced on Cain’s offering, which suggests that his offering (or his heart) was deficient according to God’s requirement (Gen. 4:3–8); the first and second commandments, which show God’s particular care with regard to worship (Ex. 20:2–6); the incident of the golden calf, which teaches that worship cannot be offered merely in accord with our own values and tastes; the story of Nadab and Abihu and the offering of “strange fire” (Lev. 10, KJV); God’s rejection of Saul’s non-prescribed worship—God said, “To obey is better than sacrifice” (1 Sam. 15:22); and Jesus’ rejection of Pharisaical worship according to the “tradition of the elders” (Matt. 15:1–14). All these indicate a rejection of worship offered according to values and directions other than those specified in Scripture.