This is a great question. Here's what I think...
If I were to write my autobiography (or even if someone else were to write my biography) you would probably get a pretty good picture of who I am. In the writing, I would probably focus on the most important things in my life that helped you to understand what I want you to know about me. Would you get every little detail about me? Certainly not. Would there be more about me that you could still get to know? Absolutely!
My point is that (in my limited mind) the Bible is what God has chosen to reveal to us, and what He has deemed important for us to know. But just like reading my autobiography and being my friend are at different levels, so would the Bible and God Himself.
I'm not trying to run off is some New Age heretical ideas here, but I do believe that I certainly think that there is more to God than what He chose to reveal to us in the Word. But it is this idea that makes me REALLY look forward to getting to meet Him face-to-face! I am sure that there are not even human words right now to describe what that interaction will be like.
I guess I am just not one for limiting God in anyway...