It is true that a certain number or people . . or personality types . . . can become very rigid in their thinking when they feel that faith makes them more-right than others. They feel justified in imposing these beliefs and practices upon others . . even to the point of violence. Its the idea that "I am so right that I may need to kill you if you won't concur and obey." At that point, religious beliefs can help to lead people into crazy actions.
Some religions -- those that are most strict in their teachings and encourage absolute devotion to church leadership -- especially promote this type of thinking. But, I think for most of us, the benefits of faith are great and we don't end up committing violence or insisting that others think and act as we do. I think for the great majority of people, religious beliefs are positive.