"Why does God stay hidden? Why doesn’t God reveal himself so concretely and physically that no one could doubt his existence? I like Karl Rahner’s perspective on this. God isn’t hidden, he says, we just don’t have the eyes to see God because our eyes aren’t attuned to that kind of reality: 'We are just discovering today that one cannot picture God to oneself in an image that has been carved out of the wood of the world. This experience is not the genesis of atheism, but the discovery that the world is not God.'
"We struggle with doubt because we can’t picture God’s existence, imagine God’s reality, or feel God’s presence in our normal ways. At a certain point, our minds, imaginations, and hearts simply run out of gas, out of room, out of feeling, and leave us dry, unable to nail down the reality of God the way we’re used to nailing down most everything else. The reality of God is elusive to our conscious minds and hearts because we can’t picture, imagine, or feel God in the usual way we do these things."
(Weekly Emails from Fr. Rolheiser)