Through The Work, it becomes clear how beliefs, resistance and tension are different aspects of the same process.
Beliefs split the world into desirable and undesirable, which brings resistance to certain experiences, and then mental and physical tension.
There is a belief in the idea of I, placed on a segment of what is. Then, there is a large set of other beliefs to fill out this identity.
These beliefs tell what is desirable and what is undesirable, so there will be a natural resistance to certain experiences - to certain situations, circumstances, sensations, emotions, thoughts and behaviors.
And this resistance is reflected in tension, both mentally and physically.
From here, it goes into the perceived need to use force, manipulation and so on, which further amplifies the tension and the sense of struggle and drama.
And it is all a struggle within content, pitting one aspect of content against another. All arising within and as Ground, as form and empty clear awareness.