Here are FIVE passages from ACIM telling us about a body which is not sick, cannot suffer, cannot die, and symbolizes immortality.
"****The body can become a sign of life****, a promise of redemption, and a ***breath of immortality*** to those grown sick of breathing in the fetid scent of death. Let it have healing as its PURPOSE. Then will it send forth the message it received, and ***by its health and loveliness*** proclaim the truth and value that it represents. Let it receive the power to ****represent an endless life, forever unattacked.**** And to your brother let its message be, "Behold me, brother, at your hand I live."
"Now in the hands made gentle by His touch, ***the Holy Spirit lays a picture of a DIFFERENT you. It is a picture of a body still***, for what you REALLY are can not be seen nor pictured. But THIS one has NOT been used for purpose of attack, and therefore never suffered pain at all.****IT witnesses to the eternal truth that you can not BE hurt****, and points BEYOND itself to both YOUR innocence and HIS.
Show THIS unto your brother, who will see that ****every scar is healed****, and every tear is wiped away in laughter and in love. And he will look on his forgiveness there, and with healed eyes will look BEYOND it, to the innocence that he beholds in you. Here is the proof that he has NEVER sinned; that NOTHING that his madness bid him do was ever done, or ever had effects of any kind. That NO reproach he laid upon his heart was EVER justified, and NO attack can touch him with the poisoned sting of fear. Attest his innocence and NOT his guilt. ****YOUR healing is his comfort and HIS health.**** BECAUSE it proves illusions were not true."
"The central lesson is always this; that what you use the body for it will become to you.Use it for sin or for attack, which is the same as sin, and you will see it as sinful. Because it is sinful it is weak, and being weak, it suffers and it dies.Use it to bring the Word of God to those who have it not, and ****the body becomes holy. Because it is holy it cannot be sick, nor can it die****. When its usefulness is done it is laid by, and that is all. The mind makes this decision, as it makes all decisions that are responsible for the body's condition. Yet the teacher of God does not make this decision alone. To do that would be to give the body another purpose from the one that keeps it holy.God's Voice will tell him when he has fulfilled his role, just as It tells him what his function is. ****He does not suffer either in going or remaining. Sickness is now impossible to him.****"
"****Now is the body healed**** because the source of sickness has been opened to relief."
"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.****
Yet this protection needs to be preserved by careful watching. If you let your mind harbor attack thoughts, yield to judgement or make plans against uncertainties to come, you have again misplaced yourself, and made a bodily identity which will attack the body, for the mind is sick. Give instant remedy, should this occur, by not allowing your defensiveness to hurt you longer."
"Very simply, the resurrection is the overcoming or surmounting of death. It is a reawakening or a rebirth; a change of mind about the meaning of the world. It is the acceptance of the Holy Spirit's interpretation of the world's purpose; the acceptance of the Atonement for oneself. It is the end of dreams of misery, and the glad awareness of the Holy Spirit's final dream. It is the recognition of the gifts of God. It is the dream ****in which the body functions perfectly****, having no function except communication."