When a person uses the mechanism of surrender and lets go of a negative feeling, the muscle testing (method) we have described will change from weak to strong. As negative thoughts or belief systems are surrendered, they no longer have the power to deplete our energy.
We are subject only to what we hold in mind. The body will respond to what we believe. If we believe that a certain substance is bad for us, then it will usually test weak with muscle testing. The same substance will make another person who believes that it is good for them strong. What is stressful to us, therefore, is primarily subjective. Muscle testing is responsible to unconscious belief systems as well as conscious ones. Testing often reveals that a person unconsciously feels or believes the opposite of what they think they consciously believe they want to heal but unconsciously be attached to the payoffs of illness. A simple muscle test reveals the truth of the matter.
Letting Go: The Pathway of Surrender, Ch. 14, pg. 207-208