Everything in the Universe vibrates. The physical body is composed of many vibrations each with specific purposes or goals in mind. Starting at the molecular level, we experience a single molecule pulsating at its own rhythm. Similar molecules are picking up on this same rhythm and begin to vibrate at the same rate, thereby creating harmony. Pretty soon you have a group of molecules with a specific purpose in mind - say to operate the heart or stomach.
Molecules are of a group soul nature, meaning that they tend to go along with the crowd.
If a molecule of a different vibration enters the group and begins to convince several of the others to go along with his rhythm, the process of dis-harmony begins. What keeps these negative molecules out of power is your ability to have dominion over your energy system. This ability lies in the focused power of your mind. This example can be taken to micro and macrocosmic levels.