What is a belief but an idea in our mind. What is our mind? Where is it? How did it come about? Our mind isn't us. Neither are the contents: our thoughts. or our our visualizations. They temporarily belong to us. But we can hardly say we own them. Sometimes we don't want to own the thoughts that arise within us. At other times we do.
To be 'owned' by a certain entanglement, a conglommerate of thought-patterns is a belief. A belief can become so entrenched and our consciousness so entangled within it, that it becomes an obsession. Real Self knowledge is, it seems to me, the only way out of all of this. But how many are willing to take responsibility for their own disentanglement?
It really seems crazy to me that people get so uptight that they would hurt another who has a different idea in their mind than their own. And as for waging a holy war because another doesn't share our belief, that's sheer insanity.