On Why the Second Commandment is not Merely a Reiteration of the First:
“If it stood alone, it would be natural to suppose that it refers to the worship of images of gods other than Jehovah — the Babylonian idol worship, for instance, which Isaiah derided (Is 44:9-20; 46:6-7), or the paganism of the Greco-Roman world of Paul’s day, of which he wrote in Romans 1:23,35 that they “exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles….They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator.” But in its context the second commandment can hardly be referring to this sort of idolatry, for if it were it would simply be repeating the thought of the first commandment without adding anything to it.
Accordingly, we take the second commandment–as in fact it has always been taken–as pointing us to the principle that (to quote Charles Hodge) “idolatry consists not only in the worship of false gods, but also in the worship of the true God by images.” In its Christian application, this means that we are not to make use of visual or pictorial representations of the triune God, or of any person of the Trinity, for the purposes of Christian worship. The commandment thus deals not with the object of our worship, but with the manner of it; what it tells us is that statutes and pictures of the One whom we worship are not to be used as an aid to worshiping him.”
~Knowing God, Chapter 2 – The Only True God, pages 43-44.
After this passage, Packer notes that Christians today differ in opinion as to whether or not all images are prohibited for teaching and instruction. He then focuses on the use of images in worship, giving reasons as to why images are not so helpful or truthful as many suppose. His reasons, in brief, are:
- Images dishonor God, for they obscure his glory.
- Images mislead us, for they convey false ideas about God.
Packer fleshes out these reasons in his book and also very briefly addresses arguments against using images of God for didactic or devotional purposes. A good read!