Why did the Israelites make the golden calf if God was taking care of them?
The Israelites made the golden calf by their own volition, not from need. They were not hurting, and God was going to take care of them. Yet they chose to demand a god to worship from Aaron because they did not know what had happened to Moses.
Les explains that these children of Israel were a people of choice. They did not have to have that calf; they were not hurting, and God was going to take care of them. But of their own volition and choice they told Aaron they had to have a god to worship, and they said they did not know what had happened to Moses. Later, Joshua heard the celebration and thought it was the noise of war, but Moses corrected him, saying it was the noise of singing. When Moses came near the camp, he saw the calf and the dancing, his anger waxed hot, and he broke the tables of the Ten Commandments beneath the mount. He then dealt with the calf, and he asked Aaron what the people had done to him to bring such great sin.
And when the people saw that Moses delayed to come down out of the mount, the people gathered themselves together unto Aaron, and said unto him, Up, make us gods, which shall go before us; for as for this Moses, the man that brought us up out of the land of Egypt, we wot not what is become of him.