The nation of Israel was notorious for making, worshiping, and serving graven images. In fact, later in Exodus, Israel was making a golden calf to worship as their gods while Moses was receiving the law from God. From groves to high places to Baal to various idols, Israel was a repeat offender of the Second Commandment.
Yet, God prohibited all of that in the Second Commandment. At first, we may think that this commandment is a restatement of the first - Have no other gods before me. It is an extension of the first commandment, but not merely a restatement. God already told them to have no other gods before him at all. So what is this about?
Kevin Deyoung summarized it by saying:
“If the first commandment is against worshiping the wrong God, the second commandment is against worshiping God in the wrong way.”
The Second Commandment is all about the way we worship God. Israel’s God and our God is not like any other god. He is not like any other god, therefore, He must not be worshiped the way other gods are worshiped. He is far bigger, better, and greater. He is omniscient, omnipresent, and omnipotent. This God must be worshiped for the God that He truly is!