I often ask God to reveal more of Himself to me.  I want to hear His voice.  I want to see Him the way Moses did.  And when these prayers seemingly go unanswered, I get frustrated.  But when struggling with this recently, God impressed upon my heart that He has given me much already.  For instance, I say I want to see Him, and I am reminded that He sent Jesus to the earth so that I could see Him.  I say I want to hear Him, and I am reminded that He has given me the Bible so that I can hear Him.  I do believe that God sometimes chooses to reveal Himself in other ways as well, and I have had experiences in my life that are examples of this, but for the times when I think I need more from Him, I am reminded of how much He has already given.