“You shall not make for yourself an idol in the form of anything in heaven above or on the earth beneath or in the waters below” (Exodus 20:4).
Whereas the first commandment was a prohibition against worshiping anyone other than God, this commandment focuses more on how one is to worship God. It deals with the habit in fallen man of seeking to make God into an image he can cope with and feel some control over.
The original sin of Adam was to want to be God and rule his own life. Ever since that fall, we have sought to rid ourselves of God’s authority. Our most subtle technique for doing so is refashioning our image of God. By viewing God as someone who is more like a human we can now think of ways to manipulate Him. This soon devolves into magical thinking, believing that if we can figure out the characteristic of this God and make an image like that characteristic, we have somehow captured God in the image. Having an idol of one’s god is therefore having a way to control Him. That tangible object becomes for us a sacred relic which binds us to our god and our god to us.
This is why Protestants have always been suspicious of relics and statues and icons used by Catholic and Orthodox Christians. Though they can be told over and over that such things have no special power, it is most easy for us to begin to invest them with special power. But vestiges of this wrong perspective can be seen in superstitions about how to get God to hear us or objects we invest with “magical” power.
Our most subtle idolatry consists, however, of distorted views of God that shape our practice of our faith. For example, the wrong belief made most obvious in Job is that God will always reward in this life our obedience or punish our disobedience. Job, his friends believe, is suffering because he has been disobedient. If this is true it enables believers to determine their future and the way God must respond based on our behavior. A version of this is the prosperity gospel with its belief that God is most concerned about our prosperity and if we have enough faith in Him He will honor all our requests for healing, riches and success. Psalm 73 gives expression to this view and the corrective Asaph, the psalmist, learned when God would not be controlled by his requirements of God and Asaph nearly then lost his faith.
God will not be controlled by any human. No image can capture Him. He is the incomparable sovereign of the universe before whom we must always bow and worship in truth.