Through the Holy Spirit, any act of healing or correction is possible on any level, including what we call the physical body level.
There are many things in ACIM which many people don't believe can be literal because it seems to be so radical and unbelievable to the ego, way outside your comfort zone, and just too 'unreal' to seem real.
But the Holy Spirit is not a metaphor. He is not just some Course lingo for some fiction aspect of an imaginary trinity that doesn't really exist in Oneness.
Also, by the way, Jesus had supernatural powers because of the Holy Spirit.
Turning water into wine, is not a metaphor. Healing the blind and sick and deaf is not a metaphor. Raising the dead is not a metaphor. Turning a stick into a snake and back is not a metaphor. The resurrection from the cross is not a metaphor. Multiplying some fish and bread to feed 5000 people is not a metaphor.
These are not just conveniently dismissed and put into a nice tidy box just to fit into our nice protected little ego frameworks of how much truth is acceptable.
ACIM says "I do not feel guilty, because the Holy Spirit will undo all the consequences of my wrong decision if I will let Him. I choose to let Him, by allowing Him to decide for God for me."
Now. Get this. When you surrender, a lot, with a genuine willingness to admit to the truth and to let go, this opens the door for the Holy Spirit to come in. He can then join with you, and He then also has access to your mind, your feelings, your energy, and your body, and also to various aspects of events and situations in your life.
If you think the Holy Spirit is inactive, passive, just an observer, or just a lifeless metaphor - some fictional concept that makes it easier to grasp metaphysics, think again.
The Holy Spirit is God's ANSWER to the separation. The answer to the ENTIRE separation. Not just an answer like some piece of information. He is an experiential answer, the actual correction OF the problem. He has the power to undo the entire universe. He has the power to correct all problems. He has the power to reverse all sickness and suffering and signs of disease on any level. He has the capability to perform MIRACLES.
Now, when you surrender a lot and relax and INVITE HIM IN, and are genuinely open to allowing Him to work in you, He can and WILL come into you. "Holy Spirit, come", is a very simple invitation. And if you are genuinely open to this, He will enter your mind/emotions/body and start to do healing on you. He can remove stuff for you. He can cancel out negative feelings. He can heal physical sickness. He can correct the body in any way needed. And this has nothing to do with the pros, cons, rights or wrongs or whether it is okay or not to heal the body. Fuck that. He just does it, ok? Get over yourself.
Now. Willingness plays into this, therefore, because if you are not willing to surrender your ego activities, you are not allowing Him to decide for God for you. And another way to put that is, if you are in control and won't let go, He can't help you. But if you DO let go, then He has access and can help you. And you will find as you develop a relationship with Him, that he can quite literally heal you, correct you, and restore you, not just on a level of thoughts or mind, but on all levels - mental, emotional, physical. It is ultimately irrelevant whether these levels a actually REAL or not, and we know that these things are still illusions, but nevertheless He can, does, and WILL bring about healing on any level if you are willing.
Again, this is only possible because He is NOT a metaphor. He is not just some concept to make it easy to explain the Course. He is not a principle. He is an intelligence, a power, a spiritual presence. He is an aspect of God, for Heaven's sake, having been created by God as the answer to ALL illusions. And there is nothing He cannot do to correct or change them for any reason. If there were anything He could not do to alter illusions, the Son of God would be trapped in hell forever with no way to go Home. And fortunately for us that's not the case.
Holy Spirit is here not just as a friend and comforter but as your healer, guide, mentor, and liberator. You don't have to just struggle through this on your own trying to have the proper thoughts or the right perceptions. You need to surrender and get into some serious teamwork. Let Him help you. Let Him do the work of directly correcting you... supernaturally... not just like, oh well, you know that's not the right answer, 3 points off.... try again. It's more like.... you will experience a supernatural electrical power flowing through you that literally purges you of all of the "consequences of your wrong decision". Mental, emotional, physical, it doesn't matter.
Miracles, my friends. Miracles.