For many generations Noah's people had been worshipping statues that they called gods. They believed that these gods would bring them good, protect them from evil, and provide all their needs. They gave their idols names such as Waddan, Suwaan, Yaghutha, Yaauga, and Nasran, according to the power they thought these gods possessed.
Allah the Almighty revealed: And they Idolaters have said: "You shall not leave your gods, nor shall you leave Wadd, nor Suwa, nor Yaghuth, nor Yauq nor Nasr (names of the idols). " Surah 71: 23
Originally these were the names of good people who had lived among them. After their deaths, statues of them were erected to keep their memories alive. After some time, however, people began to worship these statues. Later generations did not even know why they had been erected; they only knew their parents had prayed to them. That is how idol worshipping developed. Since they had no understanding of Allah the Almighty Who would punish them for their evil deeds, they became cruel and immoral.
Into this environment Allah sent Noah with His message to his people. Noah was the only intellectual not caught in the whirlpool of man's destruction which was caused by polytheism.