As an example:
One way to view them is this: Libertarians are to Government as Atheists are to Religion. Atheists want there to be no God. Libertarians want there to be no Government.
Atheists don't believe there is a God, therefore it's not a matter of them "wanting" there to be no God, that would imply they believed he existed. Nor do Libertarians want there to be no Government. They want a more limited government, one that is more true to the functions of the Constitution and one where personal freedom is not overly impacted by Government.
This article though is a good example of the misconceptions out there that exist about what Libertarianism is.