For some of them, I think it's because they feel a thing first, and then reach for justifications second. If you say something that contradicts their feelings, it won't feel true to them and they won't believe you. It doesn't matter how true it is. They're driven by emotion. It is extremely ironic that the right wing is the one that says stuff like "facts don't care about your feelings".

If you want to change minds, you probably need to make them make emotional connections to the thing you're trying to get them to believe.

Belief is also social, so if you want their beliefs to stick you need to get them away from the group that's believing nonsense/hate/whatever, or they'll go right back.