What is Voltaire trying to tell us through his novel Candide?

a commentary on the human condition. You might translate that to an assertion: "This is what it means to be human." If that's the case, then what it means to be human is to suffer, to take part in ignoble action, and to believe things that don't really work in the world.

 

If I had to boil down some of the other messages, I'd say he's saying, "Organized religion is often stupid," "War isn't noble, it is brutal," and "Much philosophy is arrogant stupidity." The best example of this  last point is Pangloss.