People have different ideas about what it is to have an “open mind”, which often tend to be along the lines of “a person who is tolerant towards tolerant beliefs”. Sometimes extra fluff is added like “does not step on other peoples beliefs, but accepts diversity”.
The problem with how people often define and use the term open minded is that it allows one to close their mind to (x) belief system if it’s deemed intolerant, which makes being open minded less about the mind and more about the heart.
If someone believes in a loving god, then you would be closed minded if you told them they’re wrong. But if they believed in a hating god, then it’s ok to tell them they’re wrong.
People also tend to only apply this definition to spiritual beliefs. If someone believed the Moon was made of cheese, then it’s ok to think that’s stupid and still be open minded. But if a belief even more ridiculous is put forward, but it’s not intolerant and is religious, then you would be close minded if you thought it was stupid.
My definition is simple. Nothing is above question. Belief, no matter how beautiful or ugly, no matter how benevolent or despicably sinister, no matter how comforting or horrifyingly painful, it may still be true.
What this means is that your pearl of truths doesn’t pass as open minded for simply being beautiful, tolerant or nice. And if you want to have an open mind, then in the words of Thomas Henry Huxley:
Sit down before fact like a little child, and be prepared to give up every preconceived notion, follow humbly wherever and to whatever abyss Nature leads or you shall learn nothing.