According to the Ten Commandments found in Exodus 20, it is clear that we are to have no other gods besides the true God. In verse 4 where we are told specifically not to make idols. Verse 5 tells us we are not to bow down to them or worship them and that to do so is a sin.
Old Testament Idolatry
The Old Testament is filled with examples of idolatry. One of the most well-known instances occurred when Moses went up on the mountain for 40 days to receive the law. While he was gone Aaron created the golden calf at the request of the Israelites. What is really amazing about this is the fact that in the previous chapter, Moses brought the people from the camp onto Mount Sinai to meet God.
They experienced the glory of God and heard his voice! They stood at the base of Mount Sinai and stared at the thick cloud of smoke that enveloped the mountain. Thunder and lightning shook the ground and the people shuddered. Moses spoke to God, and God answered in the hearing of the people. God had told them this would happen and why. In Exodus 19:9 "The LORD said to Moses, “I am going to come to you in a dense cloud, so that the people will hear when I speak with you and will always believe you” (HCSB). This means the people heard the Ten Commandments straight from God, and what was their reaction? In 19:19 they said, "You speak to us, and we will listen,” they said to Moses, “but don’t let God speak to us, or we will die” (HCSB)
So instead of hearing from God directly, they chose to send Moses. While he was gone for 40 days, they fell into idol worship even though they had heard directly from God that they were not to worship any god but Him. They went from fearing God to worshiping something made with their hands and by the time Moses came down from the mountain they were out of control.
What Is Idolatry Today?
It's easy to point a finger at idolatry of the Old Testament. The people created graven images crafted by human hands and bowed down and worshiped them. What does that mean to us today? For one thing, we must remember that before God mentioned images he said not to have other gods besides the true God. In Colossians 3:5 we are told to "… put to death what belongs to your worldly nature: sexual immorality, impurity, lust, evil desire, and greed, which is idolatry" (HCSB).
Our desire for more in all these areas is a form of idolatry. Think about how out of control the Israelites were when Moses came down from the mountain. They had offered sacrifices to the idol, and were eating, drinking, playing and even giving credit to the idol for leading them out of Egypt.
What is idolatry, today? It hasn't changed. It is the act of putting something in God's place whether it is an image, possession, person, passion, or job. Idolatry feeds our worldly nature while worship of the true God feeds our spirit.