Q. 96. What doth God require in the second commandment?
That we in no wise represent God by images, nor worship Him in any other way than He has commanded in His Word.
 Deuteronomy 4:15; Isaiah 40:18; Romans 1:23, &c., Acts 17:29;  1 Samuel 15:23; Deuteronomy 12:30.
Q. 97. Are images then not at all to be made?
God neither can, nor may be represented by any means: but as to creatures; though they may be represented, yet God forbids to make, or have any resemblance of them, either in order to worship them or to serve God by them.
 Deuteronomy 4:15–16; Isaiah 46:5; Romans 1:23;  Exodus 23:24 and 34:13–14; Numbers 33:52; Deuteronomy 7:5.
Q. 98. But may not images be tolerated in the churches, as books to the laity?
No: for we must not pretend to be wiser than God, who will have His people taught, not by dumb images, but by the lively preaching of His Word.
 Jeremiah 10:1, &c., Habakkuk 2:18–19; 2 Peter 1:19;  2 Timothy 3:16; 2 Peter 1:19.
Most of us today take it for granted that Exodus 20:3–17 should be divided into the Ten Commandments as we understand it today, namely that the Second Commandment begins with verse 4,—“Thou shalt not make unto thee any graven image…,”—and the Tenth Commandment begins with verse 17,—“Thou shalt not covet thy neighbour’s house….” Few realise that Roman Catholicism divides the commandments differently. For them, the Second Commandment begins with verse 7,—“Thou shalt not take the name of the LORD thy God in vain… ”; while their Ninth Commandment is “Thou shalt not covet thy neighbour’s house” (v. 17a), and their Tenth Commandment begins with the second part of verse 17,—“Thou shalt not covet thy neighbour’s wife….” It is easy to see how such a division would make the commandments easier on the conscience of a Catholic who is practising the veneration of images, for were the First and Second Commandments separated, it would be easy to see that the Second Commandment forbids the use of images to worship Jehovah. But when the two commandments are lumped together, it would be easy for the Catholic to reason that the prohibition against the bowing to images has to do with images of pagan gods! And at the same time it would not be difficult to justify the use of images in the church (but see Q/A 97–98).
That said, we should note that in fact, not all the Protestants in the 16th Century Reformation divided the Ten Commandments the way we do. In particular, the Lutherans kept the Roman division of the commandments. Now, the Lutherans do not use images like Rome, so is there any practical ramification to their difference with us on the Second Commandment? I am afraid so. The Reformed understanding of the Second Commandment is well expressed in the answer for Q. 96—“That we in no wise represent God by images, nor worship Him in any other way than He has commanded in His Word.” That is to say, the Second Commandment not only forbids the use of images in the worship of God, but regulates the manner in which we should worship God (images are but an instance of what is forbidden). This manner is expressed in Deuteronomy 12:32,—“What thing soever I command you, observe to do it: thou shalt not add thereto, nor diminish from it” (see context: vv. 30–31); or in other words, “whatsoever is not commanded or sanctioned in the Word of God is forbidden.” The Lutherans, not having such a stricture, would rather say: “Whatever is not forbidden is allowed.” What is the principle adopted by most modern churches, including those that profess to be Reformed or Presbyterian, today? It is not hard to tell that it is the Lutheran principle! This is the reason why many churches have no qualms about introducing puppet shows, skits, mimes, videos and slide-shows, etc., into their worship hours. These things, after all, are not expressly forbidden in the Word of God! O how many would rather please God, than pamper the flesh, and return to the old paths!
Heidelberg Catechism >