Taking the First and Second Commandments together, we learn who we are to worship and how we are not to worship. Yahweh alone is to be worshiped and he specifically says that images are not to be worshiped when we worship. Does the Second Commandment forbid the making of images altogether? It does not. In truth, God enjoys images. He is the one who made all that there is and, as the apostle teaches, “his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made.” The issue is not images. The issue is idolatry, and specifically, the use of images (or idols) by which we worship. Please notice that last preposition. By which we worship is not the same thing as in our worship, nor is it the same as the use of images when we are not worshiping.
Though it has often been the case that in Reformed circles depicting God has been frowned upon, if not downright prohibited, the Second Commandment says nothing about it. Wisdom might teach that depicting God could lead someone astray, either by encouraging worship of the depiction, or by creating a misleading image in people’s perception of what God is like. But the fact that God created men and women “in his image,” and that he fully took on our existence in the incarnation, suggests that he is not opposed to being depicted in very concrete ways. Some might counter that the two instances I mention involve his acting to reveal himself. That is true, but again, the Second Commandment involves worshiping images, not making them, even of God.
So, if something is clearly proscribed when it comes to worship, is there a guideline as to what is permitted? The best rule is twofold: keep God as the primary audience of worship throughout, and include only those elements that have biblical warrant. Following this rule, the liturgy (all churches follow a liturgy) might be complex or simple. It might feature an orchestra, or a small ensemble (that it can involve both music and musicians most certainly has biblical warrant). It might include written or extemporaneous prayers (but it should include prayer). It definitely should involve Scripture with its exposition. And celebrating the Lord’s Table when the faithful are gathered also has biblical precedent.
There are other elements that could be considered, but whatever is included should direct the congregation’s faith and devotion to the one, true, living and redeeming God. Anything else is worship of the creature and not the Creator, which is what is specifically prohibited by the First and Second Commandments.