A critical part of what you think is what you believe. Your beliefs describe what you do and why you do it. Your beliefs are your model for how reality works. Your beliefs are a description of the world in relationships of cause and effect. Your beliefs are limited by how much of the world they describe and how accurate they are.
Most people can’t list out what they believe because they’ve never really thought about it. If someone were to ask you what you believe, what would you say? How much of what you would say would be what you have carefully thought about and live up to? How much would be made up on the spot, how much would be something you wish were what you believed, and how much would be what you expect the other person wants to hear, even if it’s something you don’t believe at all? An honest person knows what they believe and why, lives their lives in accordance with their beliefs, is aware of alternative beliefs, and changes their beliefs when given sufficient reason to.
It is important to consciously define your beliefs. Subconscious beliefs can act as an unseen anchor that prevent you from accepting and acting according to better beliefs. Even when subconsciously held beliefs are better than any available alternative, you will never live them fully until you are aware of them. With every belief that you make explicit, you make identifying a superior replacement easier and acting against it more difficult.