How big is your God!

Have you ever doubted God? Have you ever doubted your life and what your doing? I remember a professor of mine in university always asked "How big is your God?" He told us that our doubts are just our lack of faith, that if we really knew God and if we really trusted him, that our doubts would disappear. Is this true? I mean, is that the pinnacle of maturity. I had a brief conversation with someone and when I didn't like their response I almost immediately said, "How big is your God? My God is big enough to take care of that problem for you." I am a person who is full of doubts and confussion when it comes to my life, however, in some areas of life I never doubt that God will provide. My goal in life is to try to remember just how big my God is and trust that he knows what he is doing and I am glad for some of the doubt, then I know the next area of my life God wants to work on!