Why we create sickness and how to reverse it

"Sickness is a decision. It is not a thing that happens to you, quite unsought, which makes you weak and brings you suffering. It is a choice you make, a plan you lay, when for an instant truth arises in your own deluded mind, and all your world appears to totter and prepare to fall. Now are you sick, that truth may go away and threaten your establishments no more."

"How do you think that sickness can succeed in shielding you from truth? Because it proves the body is not separate from you, and so you must be separate from the truth. You suffer pain because the body does, and in this pain are you made one with it. Thus is your "true" identity preserved, and the strange, haunting thought that you might be something beyond this little pile of dust silenced and stilled. For see, this dust can make you suffer, twist your limbs and stop your heart, commanding you to die and cease to be."

"Thus is the body stronger than the truth, which asks you live, but cannot overcome your choice to die. And so the body is more powerful than everlasting life, Heaven more frail than hell, and God's design for the salvation of His Son opposed by a decision stronger than His Will. His Son is dust, the Father incomplete, and chaos sits in triumph on His throne."

"Such is your planning for your own defense. And you believe that Heaven quails before such mad attacks as these, with God made blind by your illusions, truth turned into lies, and all the universe made slave to laws which your defenses would impose on it. Yet who believes illusions but the one who made them up? Who else can see them and react to them as if they were the truth?"

...AND ITS REVERSAL...

"God knows not of your plans to change His Will. The universe remains unheeding of the laws by which you thought to govern it. And Heaven has not bowed to hell, nor life to death. You can but choose to think you die, or suffer sickness or distort the truth in any way. What is created is apart from all of this. Defenses are plans to defeat what cannot be attacked. What is unalterable cannot change. And what is wholly sinless cannot sin."

"Healing will flash across your open mind, as peace and truth arise to take the place of war and vain imaginings. There will be no dark corners sickness can conceal, and keep defended from the light of truth. There will be no dim figures from your dreams, nor their obscure and meaningless pursuits with double purposes insanely sought, remaining in your mind. It will be healed of all the sickly wishes that it tried to authorize the body to obey."

"Now is the body healed, because the source of sickness has been opened to relief. And you will recognize you practiced well by this: The body should not feel at all. If you have been successful, there will be no sense of feeling ill or feeling well, of pain or pleasure. No response at all is in the mind to what the body does. Its usefulness remains and nothing more."

"Perhaps you do not realize that this removes the limits you had placed upon the body by the purposes you gave to it. As these are laid aside, the strength the body has will always be enough to serve all truly useful purposes. The body's health is fully guaranteed, because it is not limited by time, by weather or fatigue, by food and drink, or any laws you made it serve before. You need do nothing now to make it well, for sickness has become impossible."

ACIM

My note: Note that Jesus specifically refers here to healing the physical BODY, and to his intention that we PRACTICE this in order to then evaluate how well we did based on how meaningless the body is afterwards, as well as making the body invulnerable to and not dependent upon the world.