The mind can generate thought, and thought can lead to action, which can lead to result. The cause/effect principle is just to describe this universal truth. Why do you need to understand cause/effect? To understand the function of the mind. And that is the purpose. Once you have this type of real understanding, then you will know that you have to be responsible for every thought that comes from your mind. If you don’t have this type of understanding, it is difficult to augment yourself.
So when we practice Buddhism, we need to have understanding of cause and effect. The purpose of learning cause and effect is to know that you possess the mind, and mind can manifest phenomena; that is a universal truth. To understand this universal truth, that is the real goal of learning Buddhism.