Here in ACIM Chapter 2, the section on "Separation and the Atonement", Jesus spells out CLEARLY just how powerful the mind is to produce miracles.
He speaks of the combination of belief and thought with a power so great that it can LITERALLY move a physical mountain. It is not a metaphor, and it has nothing to do with mind correction or a shift in perception or an undoing of an illusion.
He also tells us that we FEAR the power of our mind and would rather believe that we have no influence, which is part of our disowning of our power and an attempt to render the mind impotent and incapable.
Jesus was able to do the kind of miracles He did because he knew how to use belief and thought combined with the Power of God/Holy Spirit to express and bring about "changes" in the world. For Him, He was performing these kinds of miracles all the time. And it is these kinds of miracles that He IS trying to teach us to become capable of in A Course in Miracles.
Why are we so afraid of this? Why do we have so many defenses against this definition of miracles? What will it take to believe it? A demonstration? Does it take a miracle to believe in miracles?
I think the ACIM community is in for a big shakeup and a probably additional layers of denial and defense, when some people start to perform these miracles consistently and convincingly. Miracles will be proven because they are demonstrations of the truth. And yet even when they are demonstrated there will be further denial.
"Few appreciate the real power of the mind, and no one remains fully aware of it all the time. However, if you hope to spare yourself from fear there are some things you must realize, and realize fully. The mind is very powerful, and never loses its creative force. It never sleeps. Every instant it is creating.
It is hard to recognize that thought and belief combine into a power surge that can literally move mountains. It appears at first glance that to believe such power about yourself is arrogant, but that is not the real reason you do not believe it.
You prefer to believe that your thoughts cannot exert real influence because you are actually afraid of them. This may allay awareness of the guilt, but at the cost of perceiving the mind as impotent. If you believe that what you think is ineffectual you may cease to be afraid of it, but you are hardly likely to respect it. There are no idle thoughts. All thinking produces form at some level."