A quote from Joel S. Goldsmith from “the Heart of Mysticism”, Acropolis Books:

Nowhere in the New Testament does the Master indicate that there is a mental cause for physical disease; nowhere does he say to anyone, “You are ill because of this, that, or the other thing”; nowhere does he say that you are being held in bondage to … It is difficult to attain this higher state of consciousness in which life is spiritually lived until one has been through the preliminary step of understanding that mind is the substance of the physical body and that mind imbued with truth will result in a completely transformed body.

The Heart of Mysticism, Joel S. Goldsmith, Acropolis Books

The video

Here is the online class video where this quote is used as an introduction to the Instrument of Truth class: