<Bang Head> Okay - let's say there's a creature called a Flump. Seeing as you don't know the creature's attributes other than its name and that it's an animal of some kind, you can't develop an opinion about it.
Now let's say that no one can prove that Flumps actually exist - however, there's a large number of people who say they do. Everyone has conflicting accounts of what this creature looks like, how the creature acts, whether it flies swims or gallops. There's another group of people who say the first group is full of shit - there is no such thing as a Flump. You, on the other hand, admit that you don't know one way or another.
You still don't know the attributes of this creature, and now you're not even sure you believe it exists. How can you develop an opinion about it?! If you haven't figured it out by now, a Flump is just a metaphor for God... It's exactly the same situation.