It is not easy to understand the writings of Jean Jacques Rousseau. It takes much thought and patience to read his books. When you finally have figured out what he's trying to say, then you have to decide whether or not you agree with it!
Take his ideas about religion, for example. At the climax of his book, The Social Contract, he carries out a historical analysis concerning the development of the relation between religion and government. He says that in the earliest phases of human history, religion and government were one. He thinks here of the ancient societies in the Fertile Crescent, and of the earliest phases of Greek, Roman, and Egyptian culture. He then identifies the emergence of Christianity as a crisis point in human history, because this new faith wants to separate religion and government. He explains that this is why ancient societies wanted so desperately to kill Christians: they found this new belief intolerable. Rousseau blames Christianity for creating a social split which has never fully healed. To this day, he says, we see religion and government as two separate things. Human society can never be fully at peace until they are reunited.
To further complicate his analysis, he makes the distinction, as do other historians, between the real Christian faith on the one hand, and what most people usually consider to be Christianity on the other. Rousseau winds up rejecting both, though, because they both lead to the social split identified earlier. Rousseau says that the only hope for human society is to get rid of Christianity in any form entirely.
In its place, he has invented his own religion. In contrast to Christianity, it has no basis in historical events; it is a collection of Rousseau's own personal ideas. Rousseau rejects the idea that God would ever freely forgive humans and extend unearned favor toward them. Instead, he wants to teach people that they must earn their own way into heaven, or be damned. Rousseau believes that his religion is central to any chance for a human society to heal itself, so he recommends that we make Christianity illegal, and require everyone to believe Rousseau's theory about God. Anyone who might reject Rousseau's made-up religion should either be exiled or put to death.
The bizarre theory of religion lies at the base of Rousseau's envisioned society, and is a part of his plan to "force people to be free."