Do you know the story of the golden calf? Moses went up on Mt. Sinai to hear from God and was up there for 40 days. The Israelites grew impatient, so they told Aaron to build them a god. He built them a golden idol that looked like a calf, and the Israelites worshiped it (Exodus 32).
Do you ever wonder how they could do that? How could they turn their backs on God repeatedly after He delivered them from slavery? Why were they prone to wander? Who would do such a thing?