"Americans are known for liking big things. Our cars, meals and homes are all pretty big compared to those found in most cultures. It's ironic then that so often our concept of God isn't very big at all. We've reduced the 'Creator of all' to the 'man upstairs' - someone understandable, explainable. No wonder we've lost our sense of wonder about God.
I'm sure we have lots of reasons for trying to shrink God down to a manageable size. We like control. We fear surrender. We crave certainty. Sometimes we're so busy trying to run the world ourselves that we overlook the opportunities we have to see and remember just how big God is. Whatever the reason, when we shrink God, the result isn't just less wonder, it's less life"
Source: Chris Mitchell from A Place for Skeptics