A thing is an idol at the point where it is worshiped as a deity. God, in that passage, was prohibiting the creation of images expressly made as deities to be worshiped. Notice that later in the **very same book**, God *commands* Moses to create the Ark of the Covenant with two carved images of cherubim (sphinx-like angels) on top of it, and this is *the* most holy relic in all of Jewish history. So: God was NOT prohibiting the making of images and he was NOT prohibiting the making of images for use in religious worship. Rather, he was forbidding the making of images that are to be used as deities.
- Jim, http://www.bible-reviews.com/
P.S. Many answers are confusing a lack of humility with idolatry. It is not their fault; it is a very common and popular teaching in many churches. Biblically, and idol is NOT "something in your life that is more important than God". What that describes is a failing to put God first; that is a failure in humility, the choice that one's *own* desires are more important than God's desires.
The Bible is clear in differentiating between those two things. "Idolatry" in the Bible *always* and *only* refers to worshiping false deities; it never refers to placing one's own desires above the will of God except in the very, very specific manner of placing one's own desire to worship false deities above the will of God..
