People who believe in religion are often accused of being narrow-minded. This is a problematic statement as people in general are narrow-minded. Religion or lack of religion has nothing to do with the state at which one choses to live or the way in which they interact with others. What I appreciate about Chesterton is that he seeks to Defamiliarize the reader with their view of social norms. In this way, the audience is able to see something in a way that has always been there, but not in a way in which it is familiar to you. As Dr. Ogden stated, this knocks you out of your comfort zone and consequently leads you to look at something in a fresh way.
This technique is imperative to examining evolution in the light of religion, or religion in the light of evolution. Moreover, it is a technique that anyone who wants to learn something must have. A person who walks into a room with preconceived views with no intention of changing them, will walk out exactly the same way. Chesterton's goal is to not allow this to happen. Despite what you may believe at any point in a conversation with him, if you can look at something in a fresh way, you have achieved the opposite of narrow-mindedness. And for Chesterton to be advocating this, especially from a religious standpoint, is to his credit as he does not allow his bias or doctrine to get in the way of seeking to help you learn something new.