How can our physical acts affect our non-physical soul?

Many of our physical actions can indeed affect our soul. This is because there is no clear dichotomy between the body, soul and spirit. They are all tightly interconnected and appear to overlap. An example of this is using an intoxicant. If someone is intoxicated, their body is feeling the toxic effects and there mind is functioning differently. Another example is brain damage: When your physical brain is damaged, your soul will obviously not be able to function how it usually does. This is because the body can almost be seen as a vehicle for the soul and spirit. If the vehicle is damaged, the driver can't hope to keep driving the same way he has been driving previously.