Natural healing is the method all living systems utilize to maintain Homeostasis. Homeostasis is, quite literally:
The ability or tendency of an organism or living system to adjust its physiological processes to maintain internal equilibrium regardless of the forces exerted upon it by the external environment
The body knows how to heal itself. We see this every day when we get a cut or a scrape. The wound bleeds, the blood forms a scab, the tissues heal from underneath, and eventually the scab is sloughed off.
Proponents of natural healing assert that this same intelligence that guides the body to repair itself from a cut or wound also has the intelligence to heal the body from any and all dis-ease.
The only reason we experience dis-ease is because we have made choices to care for our bodies in a way that thwarts this natural process. We leave it sedentary and we deprive it of rest, fresh air, fresh water, and nutrients. Then when it begins to become uncomfortable, we poison it, we stimulate it chemically, we cut parts of it out, and we treat it with radiation.
And yet even when we take such extreme measures to restore our comfort level, even though they further deprive the body of what it requires to repair itself, the body still maintains life. It is nothing short of a miracle that the majority of humans are even alive today.