The argument is that most people either believe in physical or mental cures, and they overlook the point of convergence where both modalities overlap.
Material law is only a representation of spiritual law, hence medical rules cannot contradict mental rules.
Similarly, the law that governs matter, and thus medical science, is more limited and unfree than its source—as a result, mental healing has a broader scope and efficacy than medicine, which is a gross materialization of the former.
The use of medicines and drugs cannot be avoided as long as the body's material consciousness exists, but as soon as that consciousness begins to fade, the belief in drugs fades and all bodily sufferings are seen to have their roots in the mental.
My master never mentioned the ineffectiveness of drugs, but he trained and expanded the consciousness of his students to the point where they no longer needed medicines and relied solely on mental power to heal themselves if they became ill.
When people are so engrossed in the flesh that they believe they can't live if they miss a meal, some people, both in the East and the West, fanatically deny matter and medicine. Denying the existence of matter with the same mouth that eats a steak for lunch every day is incongruent.
The only state in which we can say we don't believe in medicine, food, surgery, or the existence of matter is that state of realization in which body and mind, death and life, disease and health all appear equally elusive.
You may also want to read more about Spirituality and Healing here.
Be sure to check out my writings on Religion here.