Because worship is such an intensely personal matter, because the habits of worship become so ingrained into our lives and identities, it is easy for us to think that if we like something God must approve of it, especially when it is done as part of the worship of God. Years ago I was in a service where the table was fenced, which meant that not everyone attending the service was permitted to come to the table. After the service a person who attended protested that she was a deaconess in her congregation and that she had helped to administer communion and had never been prohibited from participating in communion before. She was incensed that the church had denied her right to participate in holy communion. Hers was a very American response. It was essentially individualistic and autonomous. Who is the visible, institutional church to tell anyone what they may or may not do in worship? Even though she was Romanist she agreed with many American evangelicals that corporate worship is the public expression of private piety. The Reformed understanding of Scripture is that private devotion is the consequence of public worship.

She also assumed that her desires were the norm by which the practice of public worship should be normed. It seems likely that most Christians assume that if something is not forbidden in public worship then it is permitted. This gets us to the second, and perhaps even more fundamental part of the commandment, which we summarize with the words: “nor worship him in any other way than he has commanded” (Heidelberg 96). This has come to be known as the Regulative Principle of Worship as distinct from the normative principle (we may do whatever is not forbidden). In recent years, Reformed folk have claimed that various things distinguish us from other Christian traditions. Some people point to the doctrine of union with Christ. Others point to the third use of the law. Well, in those two instances, it can be shown that the historic and confessional Reformed doctrine of union with Christ or the historic and confessional Reformed doctrine of the third use of the law fundamentally different from, e.g., the confessional Lutheran doctrine.

The regulative principle of worship, however, does distinguish confession Reformed and Presbyterian churches from the broad evangelical traditions, many of whom are descended from the Pietists and the Anabaptists. The confessional Lutheran churches, the Anglican church, and the Romanists all operate on the normative principle. That principle works for many things in daily life. May one cross this street? Yes, certainly. It is not forbidden. The regulative principle, however, does not work for daily life. “Must I cross this street?” It was never intended to applied to daily life, outside of public worship. In the same way, the normative principle does not work for public worship.

Here is another reason why it is so important to distinguish between that which is secular or common to all humans and that which is sacred or set apart distinctly for service to God. To be sure, believers do all to the glory of God (1 Cor 10:31) but Paul makes clear that there is a difference between a common meal and a religious meal (Compare 1 Cor 8 with 1 Cor 10:14–22). We are free to eat meat, even that which has been offered to idols but the moment someone says “this food has been offered to the gods” it is no longer a common meal. In that case it is a religious meal and Christians are no longer free to eat. It is fashionable to deny any distinction between the sacred and the secular or common but such a denial contradicts two millennia of Christian teaching, which is grounded in the Scriptures.

Worship is sacred, not secular or common. In public worship and in Christian instruction we do not ask, “may we do it” but “what has God commanded?” These are two distinct questions. In public worship we do that and only that which God has commanded. In our understanding of the second commandment the Reformed churches have applied the sola Scriptura principle and the second commandment to arrive at this principle. It was implicit in the Fathers but it is explicit in Scripture. Sola Scriptura is short hand for the sufficiency of Scripture. If there is anything for which Scripture is sufficient, it is the governance of public worship:

You shall surely destroy all the places where the nations whom you shall dispossess served their gods, on the high mountains and on the hills and under every green tree. You shall tear down their altars and dash in pieces their pillars and burn their Asherim with fire. You shall chop down the carved images of their gods and destroy their name out of that place. You shall not worship Yahweh your God in that way. But you shall seek the place that Yahweh your God will choose out of all your tribes to put his name and make his habitation there. There you shall go, and there you shall bring your burnt offerings and your sacrifices, your tithes and the contribution that you present, your vow offerings, your freewill offerings, and the firstborn of your herd and of your flock (Deut 12:2–8; emphasis added).

Not only did Yahweh demand that we worship him alone but he reserved for himself the right to determine where and how he was to be worshipped. “You shall not worship Yahweh your God in that way” is an explicit articulation of the regulative principle. If there is a verse on which we need to meditate it is Deuteronomy 12:4. Yahweh has not changed. It is not as if in the old covenant he was strict but now, in the new covenant, he is indifferent about how he is worshipped. First, to think such a thing is to fall into the Gnostic and Marcionite heresy that there is one god of the old covenant and another of the new. Second, Hebrews 12:28b–29 specifically teaches the contrary: “let us offer to God acceptable worship, with reverence and awe, for our God is a consuming fire.” This is the language of the Old Testament.

The regulative principle of worship is something which the Reformed tradition has something to offer to other Christian traditions. This is a place where we have preserved the apostolic and ancient Christian teaching in a way that the other wings of the church have not.

There remains a more difficult question for those of us who confess the Reformed faith: do we still believe our own confession? It is one thing to recite and affirm Heidelberg 96–98 but it is another thing to practice what we confess. I say this because the reality is that modern Reformed practice has drifted a fair bit from the original understanding and practice of this commandment. Our sixteenth- and seventeenth-century worship services looked quite like those of the second-century. We mostly sang God’s Word and we did so a cappella, i.e., without musical instruments. By the 16th century, the use of musical instruments in public Christian worship was only about 300 years old. In the late 13th century, Thomas Aquinas (d. 1274) could say without fear of contradiction that the use of musical instruments in public worship is “Judaizing,” by which he meant an unwarranted return to Mosaic and Davidic practice.

The historical reality is that most of the church, for most of its history, until very recently, worshipped without musical instruments. Sometimes people think that singing a cappella is a Reformed oddity but it is not so. The organ was introduced into public worship in the 7th century but its use was not widespread. When the Reformers removed musical instruments (mainly organs) from the Reformed and Presbyterian churches in the 16th century, they were a novelty. The Reformers were returning to Apostolic and to ancient Christian practice. There were no musical instruments used in the worship of the apostolic churches. There were no instruments used in worship by the early church. The early church fathers rejected them explicitly on two grounds: that they were belonged to the typological, sacrificial system (see 2 Chronicles 29) which has been fulfilled by Christ and that they were associated with pagan worship.

So, if the apostles did not use them, if the ancient church did not use them, if even Aquinas recognized that they were a corruption, if the Reformed churches uniformly rejected them in the 16th and 17th centuries why did we re-institute them in the 18th and 19th centuries? See the relevant chapters in Recovering the Reformed Confession where I explored this history.

Why does virtually every confessional Reformed congregation today use musical instruments in public worship? Well, ask them. What do they say? Most of the time the answer is: “We like it. The aesthetics are better.” Let me ask you again: what is our principle? We may worship God than in no other way than he has commanded in his Word. We do not confess an aesthetic nor do we confess a preference.

Sometimes the use of instruments in public worship is defended on the basis that they are only circumstances. Were they only circumstantial to the practice of worship in 2 Chronicles 29? Our Reformed forefathers did not think so. Were musical instruments really indifferent (adiaphora) then we should be able eliminate them without controversy but experience suggests that is not what would happen in most places.

According to Calvin, the Heidelberg theologians, the Dutch Reformed churches in the 16th and 17th centuries and the Westminster Divines, all those instruments were covered with the blood of bulls and goats. They were types of heaven—which is why they appear in the book of the Revelation by the way, not as instructions for New Testament worship—and of Christ, fulfilled by Christ. That’s why our forefathers sang the Psalms but did not commit holy war or use instruments, even though the Psalms tell us to do both, because they realized that holy war and instruments belonged to the period of types and shadows.

Again, as with pictures of Jesus, can so many congregations be wrong? Yes. It happened in the late middle ages and we had a Reformation. It can happen again. It took us time to get here and we do not want the civil authorities to cleanse the churches (as they sometimes did during the Reformation) now so we have to persuade each other of the truth and right understanding of God’s Word as we confess it. That will take time. Let us be patient. Let us be gracious and pray for a renewed common understanding of the second commandment again.

The presence of pictures of Christ in our churches and in our Christian education curricula and arguments over worship style are symptoms of our struggle with our own past and confession. In some cases we have simply lost track of what we believe and confess. In some cases our confession has been rejected. These are difficult questions that we need to face, not merely to achieve Reformation but to recover our own theology, piety, and practice.

Note: If the the RPW is a new category for you or if you have not read Recovering the Reformed Confession or if you have not not read the posts in this category (linked above), please do that first.

Here are all the posts on the Heidelberg Catechism.