#2. "Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth."
Tantamount to the First Commandment, what follows is a practical instruction on how not to be tempted to disobey it (see Romans 13:14). Asherah poles, statues of marble and stone and bronze and gold (and clay and iron). Unbelievers proceeded to form these with their hands using gifts of craftsmanship they'd been given by God (see Deuteronomy 27:15). Then, I believe the devil and his angels imbued the peoples' creations with their presence. Sort of like a negative lightning rod. Creepy. How else might one be tempted to worship a lifeless statue? Consider the modern impracticality of prostrating yourself before a golden calf. Ask anyone on the street (not Broad Street in New York, that bull's bronze) to do that and they'd think you're crazy.
It was against God's Law to try and form any likeness of Him. Doing so would circumnavigate the vital necessity of seeing Him, knowing Him and worshiping Him with your heart (that's where you see Him). This surely would keep out the riffraff. If you found yourself needing an object to venerate in place of God, I should like to hope you'd be wise enough to realize your mistake and repent of your idolatry. But that's the point, right? If you needed an thing to worship then you obviously weren't seeing God with your heart, you weren't walking with Him and therefore didn't know Him.
Paul was wise enough to use this to his advantage. In Athens, He came upon an altar to THE UNKNOWN GOD. At least the ultra-superstitious Athenians were honest. They didn't know God and the inscription on the altar admitted as much. I think God could work with that. And He did (see Acts 17:21-34).
In closing, I refer to Paul's comparison of the believer to a "vessel of honour" (2 Timothy 2:20). The distinction though, is that God is the one who formed us and filled us with His Holy Spirit.