Candide caused great controversy when published, but also enjoyed great success, and to this day, it probably remains one of the most widely read of Voltaire's writings. Following its publication, it was banned with the argument that it contained religious blasphemy and political sedition. Candide reflects Voltaire’s lifelong aversion to Christian orthodoxy, as well as the pretensions of nobility, but particularly the school of optimism, as ascribed to Leibniz, that is, the belief that we are living in the best of all possible worlds, because God could not have created an imperfect world. This is a theme Voltaire will come back throughout the whole novella, either directly, or indirectly through what the characters go through.
Many events, including a catastrophic earthquake in Lisbon in 1755 claiming tens of thousands of lives, and a war around this period (Seven Years’ War), contributed to the writing of this novella. Voltaire's mood must have contrasted sharply with the optimism he bashed in this satire.
Candide is a polemical book in nature and as such, it is better appreciated in context. However, many of the institutions Voltaire struggled with are universal, others have just undergone some cosmetic changes, and his witty criticism of these institutions is timeless.