If medieval and early modern Christianity had a pessimistic view of human nature in which man is innately sinful and can only be kept in check by Church and State, we moderns tend to have a rather optimistic view of human nature that stresses man's innate natural goodness. This too has consequences for both theology and politics. If man is good then it stands to reason that he can achieve salvation through his own means without the aid of the Church. Now it becomes possible to talk about human reason as the bar against which to judge all things. Only someone confident in the intrinsic goodness of human beings could allow them to judge the world around them and do it based on what is innate to them. As for politics, a belief in human goodness allows for human beings to craft their own laws. We can even begin to talk about government as a contract between equals instead of the dictates of a patriarch to his children, leading to liberal democracy.
The legacy of this notion of human goodness still presents itself in our debates over crime and punishment and foreign policy. Why do people commit crimes? A conservative would say it is because they are "bad" people, motivated by greed and malice. In order to protect itself, society must remove this person from its midsts, either through prison or even the death penalty. Punishment is something that the person deserves as his just deserts. In the liberal model crime results from either mental illness, being raised in a problematic society or simply bad education. One way or another it is not the person's fault and the purpose of any "punishment" is not to penalize the person, but "rehabilitate" them. (See "C. S. Lewis on the Implications of the Nazi Holocaust.") Why are there terrorists? The conservative will tell you that it is because they are "evil" and hate "freedom." Naturally, such people can only be stopped by invading other countries and killing those people who deserve it. The liberal will tell that terrorists are the products of economic inequality, the legacy of colonialism and a fundamentalist education that preaches hate. Agree to peace talks, address the massive economic inequalities across the globe and provide a proper education for all and terrorism will disappear.
Now even the liberal acknowledges that there is much that is wrong with the world. Rather then lay the blame on people, the blame is placed on society. It is society that creates inequalities and teaches prejudice. People, left to their own devices, would naturally wish to live in harmony with others, recognizing the common humanity of all, and would not be bothered by the existence of other races and creeds. People have to be taught to hate others because of the color of their skin and the deity they pray to. The good news is that people can be saved from their own prejudices. With a properly funded welfare program, civil rights legislation and tolerant education, the natural human goodness in people will reassert itself and stand against all the ills created by society in the first place.
This brings us to Candide, a novel that represents this Enlightenment shift in how one views humanity. Candide is naturally good. Contrary to a simplistic view of the character, Candide is not stupid (a mistake made by the modern day adaptation, Forrest Gump
It is for this reason that Voltaire subverts the garden of Eden story. Instead of Adam and Eve committing Original Sin, willfully disobeying the divine commandment to not eat from the tree of knowledge, and being rightfully thrown out of paradise, Candide has no notion of sin. He only wishes to experiment with the laws of "cause and effect." The fact that he kisses Cunegonde is interpreted as sin by a corrupt society, leading to him being wrongfully exiled from his beloved home in Westphalia. Instead of degenerate humans needing to be saved by righteous laws, Candide is the pure one, it is the outside system that is degenerate.