Originally Posted by MS Fowler

You are evidently using the term "religion" in a very restrictive sense, meaning an organized religion. I was using it in the much broader sense of beliefs. No deity required. Nothing supernatural -- just "beliefs" that are not subject to rational proof or verification.
You may reject the supernatural, but that is still a "belief". You cannot "prove" that the supernatural does not exist. You may live your life in the light of your belief, but it remains, merely, a belief.