If nobody believed in superstition it would be unable to hurt anyone


The story of Knock in the light of Hume's case against believability of miracles
On the night of the 21st of August 1879 the Virgin Mary flanked by St Joseph and a bishop thought to be St John the Evangelist and an altar with a lamb and cross on it allegedly appeared on the gable wall of the Parish Church for a few hours. Fifteen people witnessed the vision including a child of five (page 60, The Evidence for Visions of the Virgin Mary) and stood watching it for two hours allegedly in torrential rain.
Religion is being completely irrational in saying, "Yes miracles are improbable. But if the evidence is good enough for them then we can believe they happened. Improbable things do happen. We merely say that its probable but not proven that Mary was at Knock." It is rational to pay no attention to evidence relating to a miracle being authentic if there is evidence that the event is not a true miracle. The stronger the case for an event's non-supernaturality, the less right you have to assume or believe that its supernatural even if there is evidence for it being miraculous or paranormal.

David Hume said that however honest a witness to a miracle seems, it is more likely for the witness to be lying than for the witness to be telling the truth.
Christianity rejects this argument. It says it could be likely for the witness to be telling the truth. It says its unfair to argue that a person is to be doubted just because they said they experienced a miracle. Thus believing them is an act of Christian love. But even Christians say, "If an unreliable person testifies to a miracle we don't have to believe. We should not." To that we can say, "But its unfair to argue that they must be given no credibility just because they spoke of a miracle?" The only sensible approach then is to argue, "We will not consider miracle claims. Period." Its the only way to avoid opening the floodgates.
We are not doing that to be unfair but to be fair. Knock might seem okay but when you think of what miracles imply it is clear that Knock is toxic and superstitious.
Judith Campbell left her dying mother to go and see the vision. The old woman tried to venture out of the house alone and was found dying at the door. By even Catholic standards, Judy Campbell should not be believed when she testified to the apparition.
Evidence gives us reasonable grounds for accepting something as probably true. Evidence itself however is based on assumptions. If you are calculating your friend's tax you assume that the paperwork he gives you is real though you know it might not be. You assume that its human factors to blame if its faked. You do not assume some being from another dimension faked it. That is all an unbeliever in miracles is doing. He is assuming what everybody else assumes. Some believers in miracles say they assume that sometimes the supernatural is at work. Assuming such a thing would be irrational. It would be arbitrary for you assume one miracle is true and the other is false. So most believers prefer to deny that they assume - they say they only believe something is miraculous when there is evidence that it is. But evidence requires that you assume there is no supernatural...

The accusation that unbelievers are too narrow-minded to believe is totally unfair ...
It's the believers who are narrow and unfair...and implicitly dangerous. They could have the world going mad believing all kinds of stupid and irresponsible rubbish.