Hobbes, Bossuet, and Locke all embraced some form of the Christian belief system (either Anglicanism or Roman Catholicism). While Rousseau affirmed the necessity of religion, he repudiated the doctrine of original sen, which plays so large a part in all different versions of Christianity (in Émile, Rousseau writes "there is no original perversity in the human hear"). His endorsement of religious toleration would be ironic, had he not meant it seriously: he claims to be tolerant, but in the same chapter of the Social Contract demands that anyone who doesn't agree with his idea of a "civil religion" be put to death! His assertion that true followers of Jesus would not make good citizens was based on his claim that Christian soldiers wouldn't fight as savagely as pagan soldiers.
Rousseau's political critique of Christianity was twofold: first, that it divided religion from the government; second, that Christianity asserts that no ordinary human is perfect. Rousseau, on the other hand, believed that religion had to be united and intertwined with the government, and that human beings are born perfect: and that human beings and human society can be perfected and kept perfect if only we will follow his guidelines!