Voltaire wrote Candide for many reasons. He used it to present his opinions on the state of society and on the ideas and theories put forth by his contemporaries. He used the character of Pangloss to satire Leibnitz and his view that this world was the best world because God had created it. All of the misery and greif shown in the story, and the constant referral by Candide to Pangloss' philosophy is meant to show Leinbitz to be a fool. Candide is also meant to show Voltaire's pessimistic view on the human being and on society. He shows the perfect society of el dorado in order to demonstrate to Candide how corrupt and full of prejudice (relating to religion, class, etc) his society was, but instead Candide and Cacambo showed their greed by leaving el dorado with gold and jewels in order to gain wealth and notoriety in their world. Voltaire was even as specific as to attack Elie-Catherine Freron, a critic of his, in Candide by making her the insufferable critic at the French play. To make a long story short, Voltaire was trying to make everyone see how ridiculous and dumb they looked to be involved in petty squabbles on religion or class when none of that mattered. He is stressing the importance of equality, and his belief that humans cause their own misery thru greed and prejudice.
             Voltaire lived in a time when Europe was very much a devoutly religious, autocratic society, but the advent of science and geology were challenging convention, such as the creation of the world in seven days, and the precise age of the earth. It was believed that everyone was born with all their thoughts and ideas ready in thier heads, their fate set out and their whole existence mapped. Following Leibnitz's doctrine of Optimism - that is, that this is the best of all possible worlds, thus everything happens for the best - meant that people did not challenge oppression. Voltaire and the other philosophes of the enlightenment challeneged this view, though...