Jesus said, “For judgment I came into this world, that those who do not see may see, and those who see may become blind.” Some of the Pharisees near him heard these things, and said to him, “Are we also blind?” Jesus said to them, “If you were blind, you would have no guilt; but now that you say, “˜We see,’ your guilt remains.” (John 9:39-41)
As an eye doctor, I am always amazed at how many have great eyesight, but poor vision; and how many that have poor eyesight, but great vision. This can true in general with people, but especially so in terms of one's spiritual understanding.