I explained in more depth elsewhere, but basically, Nihilism is the natural logical conclusion for a philosophy that does not have a basis in God.

Therefore, understanding Nihilism should be important; not because it is right, but because in it's own way, it points TO God. While I've only read portions of Nietzsche's writings, I believe he understood this as well.

I could explain in more depth but you probably understand me without it! If someone wants to understand more of what I mean, feel free to ask!