The Second Commandment in its narrow sense prohibits the worship of images themselves—“You shall not make for yourself an idol [lit. ‘carved image’]… You shall not worship them or serve them” (Exodus 20:5, NASB95). By extension, the Reformed have held this to mean we should not use images in worship or to aid in worship in any way, though many Christian traditions disagree (especially Catholics and Orthodox).
However, in its broad sense, the Second Commandment regulates the entirety of how we worship God. It prohibits us form worshipping God in a way not prescribed in His Word. Stated positively, we should only worship God the way He has set down for us in His Word. This principle is known as the Regulative Principle of Worship (RPW). The RPW is seen in Westminster Confession of Faith 21.1, which says,
the acceptable way of worshiping the true God is instituted by himself, and so limited by his own revealed will, that he may not be worshiped 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.
The RPW is also set forth in Westminster Shorter Catechism 50 and 51 on the Second Commandment. WSC 50 says, “The second commandment requireth the receiving, observing, and keeping pure and entire, all such religious worship and ordinances as God hath appointed in his word.” WSC 51 adds, “The second commandment forbiddeth the worshiping of God by images, or any other way not appointed in his word.”
So it is both: (1) We must practice that which God has set down in His Word regarding worship, (2) and we must not worship God in any way He has not set down.
Deuteronomy 12 and the Second Commandment
This point is made in Deuteronomy 12, a chapter that covers the Second Commandment in Moses’ final sermon to Israel before they crossed the Jordan River into Canaan. After restating the Ten Commandments in Deuteronomy 5, Moses gave commands falling under each of the Ten Commandments in chapters 6–26. Deuteronomy 6–11 covers the First Commandment, urging Israel to give undivided loyalty to the Lord. Then Deuteronomy 12 follows by giving laws regarding the Second Commandment. What this means is Deuteronomy 12 contains a God-inspired exposition and application of the Second Commandment. It is the exposition of Moses himself, breathed out by the Spirit of God.
In Deuteronomy 12, Moses instructed Israel regarding worship as they entered the Promised Land of Canaan. He told Israel to destroy the all the places of Canaanite false worship—including tearing down altars, burning Asherim poles, and cutting down engraved images (Deuteronomy 12:3). Then in 12:4, Moses said, “You shall not act like this toward the LORD your God” (NASB95). In other words, Moses was saying ‘you are not to worship God this way.’ As the next verse says, “But you shall seek the LORD at the place which the LORD your God will choose from all your tribes, to establish His name there for His dwelling, and there you shall come” (Deuteronomy 12:5). This instruction makes the point that we are to worship God the way He tells us.
This is contrasted with Deuteronomy 12:8, “You shall not do at all what we are doing here today, every man doing whatever is right in his own eyes,” language echoed in the book of Judges (Judges 17:6; 21:25). Instead of God’s people worshipping God however they desire, Moses gives specific rules for proper sacrifices for Israel (Deuteronomy 12:13-28). Is this not how the whole Old Testament works? It gives detailed instruction for sacrifices and the worship of God. He tells us exactly how to worship Him.
The last four verses in Deuteronomy 12 (vv. 29-32) are important for the manner of worship. Moses says that when you come into Canaan, “beware that you are not ensnared to follow them [the nations], after they are destroyed before you, and that you do not inquire after their gods, saying, ‘How do these nations serve their gods, that I also may do likewise?’” (12:30). Moses said, “You shall not behave thus toward the LORD your God, for every abominable act which the LORD hates they have done for their gods; for they even burn their sons and daughters in the fire to their gods” (12:31). We may summarize this as follows—do not look to those who do not worship the Lord for instruction as to how we are to worship the Lord. Moses then said:
Whatever I command you, you shall be careful to do; you shall not add to nor take away from it. (Deuteronomy 12:32)
This is an essential verse, and it is clear—worship God the way He has commanded. Do not add to His command, and do not take away from His command. No more, no less. And you certainly do not look to the way the pagans worship their false gods.
Yet is this not what the church so often does today? Many churches look at rock concerts and say, ‘hey those are popular and everyone gets excited there.’ So they turn the worship of God into a concert. However, God never tells us to have people perform for others. That is not biblical worship. Rather, He tells us to sing—“addressing one another in psalms and hymns and spiritual songs, singing and making melody to the Lord with your heart” (Ephesians 5:19). We sing songs to worship God, and we do it together (i.e., congregational singing). And everything we do regarding worship music, including the songs we choose, should aid such singing.
Elements and Circumstances
Deuteronomy 12 and the Second Commandment teach that our worship must follow God’s command. So everything we do in public worship must have a biblical basis. We do not have dances in worship because there is no command to do so. Instead, we do that which is commanded:
The reading of the Word
The teaching and preaching of the Word
The singing of the Word
Prayers to God
The administration of the sacraments
Confession of sin
Confession of our faith
The collection of the offering
The taking of vows to God
All these “elements” have an explicit biblical basis for them. That is all we are supposed to do in worship. And we must do them. No more, no less. This is what Westminster Larger Catechism 108 (with its biblical proof-texts) sets forth:
The duties required in the second commandment are, the receiving, observing, and keeping pure and entire, all such religious worship and ordinances as God hath instituted in his word; particularly prayer and thanksgiving in the name of Christ; the reading, preaching, and hearing of the word; the administration and receiving of the sacraments; church government and discipline; the ministry and maintenance thereof; religious fasting; swearing by the name of God, and vowing unto him: as also the disapproving, detesting, opposing, all false worship; and, according to each one’s place and calling, removing it, and all monuments of idolatry.
Now the “circumstances” of such worship may vary. God does not tell us to worship at 9 am or 10 am. He does not tell us how many songs we should sing in a service. He does not tell us how often we should celebrate the Lord’s Supper. He does not tell us every prayer we should pray or which instruments to use or when to sit and stand in the service. These things require wisdom and the application of biblical principles. So we distinguish between the elements (which are commanded) and the circumstances (which require wisdom and reason).
Caution from Nadab and Abihu
While addressing the circumstances of worship is not always easy, we must be careful to worship the Lord only in a manner He has commanded. Recall the story of Nadab and Abihu, Aaron’s sons who served as priests. Leviticus 10:1-2 says they “offered strange fire before the LORD, which He had not commanded them. And fire came out from the presence of the LORD and consumed them, and they died before the LORD.”
God gave so many details for the priests and worship. Yet Nadab and Abihu did it their own way, and God struck them down for it. It is possible they violated Exodus 30:9, which says “You shall not offer any strange incense.” However, the phrase “strange fire” from Leviticus 10:1 is not found in this command of Exodus 30:9. And Leviticus 10:1 says Nadab and Abihu did that “which He had not commanded them” (not that they violated a prohibition).
So this seems to have been violation of the Regulative Principle of Worship (RPW)—Nadab and Abihu did that which God did not command them to do. Thus we see that God takes His worship seriously. He is zealous for it. So we too must be zealous for His worship and obey.
In fact, part of the Reformed tradition is following the RPW. The Reformation was not just about God’s sovereignty in salvation or justification by faith. The Reformation was also about worship. And to be a Reformed Christian means to worship the way God tells us. This is actually a rather simple form of worship. Simple but rich. We are not showy, and we do not seek to impress others according to the world’s standards. Rather, we seek to show forth Christ and His glory through His Word.
Words, Not Images
I do not want to make the use of images the focus here, as that is an entire topic in itself. However, it is a good example for application, as it follows from the Regulative Principle that Christians should not use images in worship or for the purpose of worship. And the reason is that God has not commanded us to use them.
There is a biblical basis for this point from Exodus 34:1, where God told Moses to “Cut out for yourself two stone tablets like the former ones, and I will write on the tablets the words that were on the former tablets which you shattered.” The verb “cut out” is phasal, which is the verb form of the noun “idol/graven image” in the Second Commandment (Exodus 20:4). Surely this language is intentional. Moses broke the stone tablets with the commandments because Israel had made the golden calf, a violation of the Second Commandment (Exodus 32:19). In response, Moses was to “cut out” tablets for a new set of commandments graven in stone.
The point is we do not make “graven images” (KJV) for the purposes of worship because God calls us to worship Him through the “graven image” of His Word. God gives us words, not pictures. He gave Israel the Ten Commandments, but Israel followed the manner of the Canaanites by making the graven image of the golden calf. God has given us His Word through the apostles and prophets. Some Christians want to worship God through the use of images, and even “venerate” images of Christ, Mary, and saints. But that is not what God has commanded.
God commands us to worship Him through His Word. That is why we read the Word, preach the Word, pray the Word, and signify the Word through the administration of the sacraments. God communicates to us through His Word, and His Word tells us to worship Him through the Word, not images.