Sounds more like all ideologies are harmful, religious or otherwise.
It's not that ideologies are always harmful, so much as that acting without thinking can be harmful, and ideology discourages people from thinking things through for themselves.
If people are carefully and honestly thinking through the consequences of their actions, they are less likely to harm themselves or others.
If, OTOH, people are blindly following dogma rather than engaging in rational thought.... well, often that isn't an immediate problem (either because the dogma is reasonably applicable to the situation at hand, or because the consequences of the decisions being made on auto-pilot are not too severe). But it does open the door for serious harm to occur, because people who aren't thinking are not able to quickly or easily detect or amend their mistakes.