I think beliefs have done many bad things, especially organised beliefs. But that is also true for the opposite. It´s like saying „everything bad has been done by people“. Yes, true, but everything good has also been done by people because only people can do in that sense and beliefs are the reasons for all doing.
Ideas and references
Because of the bad that has happened, it is a good idea to wonder how we can choose our beliefs wisely. Over the cause of history, a lot of smart people have come up with a whole lot of very smart ideas about how to validate a belief. I´m sure there is an ethical theory that feels right for everybody. I doubt there is one that pleases all. I personally like an approach I once heard a Buddhist monk, Ajahn Brahm, talk about. His talk was about decision making in general but to me, as a counsellor, beliefs are ideas that we decide to believe in or not (anymore). Ajahn Brahm stated that it is only the decision making itself we can focus on. We can only check the process of making a decision and if it is done in the right or wrong way. We can´t validate the outcome because we don´t really control it. We will never know the future, we will never have control over all the components involved in a circumstance.
Wise decision making
According to Ajahn Brahm, a decision should not be based on
pure egoism and
lack of information.
I think the same principles can be used to check a belief. Do you believe that because you are scared of facing something else, some other truth? Do you believe it because you have been frustrated or hurt in some way and don´t want to open your heart to something? Does your belief only bring you good things/happiness? Does it hurt others? Have you considered all the information that you have? Have you done your best to get all the information that you could get?
Letting happening happen
After that, you will have to see what the future brings, at least you have done your best. If you have done wrong, do differently from now on. When you have done your best, there is no need to look back and regret your decision or wonder what you should or could have done better if you had believed differently. That is an approach I´m strongly supporting, especially because we tend to see the other path, the path we didn´t choose, in the most beautiful colours. The reality is that no path ever is only good or bad. There is always both in everything.