You can only find out what you actually believe (rather than what you think you believe) by watching how you act. You simply don’t know what you believe, before that. You are too complex to understand yourself.
If you can't understand why someone is doing something, look at the consequences of their actions, whatever they might be, and then infer the motivations from their consequences.
You're going to pay a price for every bloody thing you do and everything you don't do. You don't get to choose to not pay a price. You get to choose which poison you're going to take. That's it.