Do know why are heart rate and blood pressure go up when we feel anger, hate or other negative emotions?

Interesting idea, but unfortunately you can't really speak spiritually when discussing biological reactions and functions.

But if we're going to forge a path through this wood, then I'd suppose this: When we are in equilibrium - i.e., when we're right with God, following our destiny, living authentically, whatever you like to call it - those emotions of calm and joy will indicate your progress and success in that state.

Conversely, when we're out of sync, living inauthentically, hiding from God, etc., we instinctively feel at odds with something greater than us. As a result, our soul's unease is reflected through our body's autonomic responses.

It's a theory born off the cuff.