He had withdrawn absolutely all belief in separation, all belief in the body being the cause of anything, all victimhood, all belief in being at the effect of the world, and that means the body to Him had absolutely no further sense of apparent reality. He knew it was - LITERALLY - nothing at all. It wasn't that it still existed and was something special, or a special communication device (that was a pre-ascension state). He recognized the complete absolute truth, that there is no world and there is no body. It is NOTHING other than an illusion that isn't real.
And with that, His body literally disappeared from existence. This was the final demonstration, the final statement, that He had overcome death, that He was not a body at all, and that the body is just an illusion.
It is our task, similarly, to learn to DISAPPEAR the body, to learn to disappear sickness, to disappear death, to overcome all material laws, to reverse every sign of sin, and to recognizing that all of the things of this world are literally NOTHING. They are not a special something, or a God-filled something, or a real-something, or meaningful, or important.
"There is no world. This is the central thought the Course would aim to teach". Quite literally, Jesus's disappearing of His body foreshadows the "Disappearance of the Universe", which WILL happen when the brotherhood is again united in truth, because this world is NOTHING more than an illusion and God did not create it.
You do not need a body to exist. You do not need this world to exist. You are Immortal Spirit, forever.
Below is the quote from Jesus where He described this from the additional material given to Helen.
“My body disappeared because I had no illusion about it. The last one had gone. It was laid in the tomb, but there was nothing left to bury. It did not disintegrate because the unreal cannot die. It merely became what it always was. And that is what “rolling the stone away” means. The body disappears, and no longer hides what lies beyond. It merely ceases to interfere with vision. To roll the stone away is to see beyond the tomb, beyond death, and to understand the body’s nothingness. What is understood as nothing must disappear.
I did assume a human form with human attributes afterwards, to speak to those who were to prove the body’s worthlessness to the world. This has been much misunderstood. I came to tell them that death is illusion, and the mind that made the body can make another since form itself is an illusion. They did not understand. But now I talk to you and give you the same message. The death of an illusion means nothing. It disappears when you awaken and decide to dream no more. And you still do have the power to make this decision as I did.
God holds out His hand to His Son to help him rise and return to Him. I can help because the world is illusion, and I have overcome the world. Look past the tomb, the body, the illusion. Have faith in nothing but the spirit and the guidance God gives you. He could not have created the body because it is a limit. He must have created the spirit because it is immortal. Can those who are created like Him be limited? The body is the symbol of the world.
Leave it behind. It cannot enter Heaven. But I can take you there anytime you choose. Together we can watch the world disappear and its symbol vanish as it does so. And then, and then… I cannot speak of that.
A body cannot stay without illusions, and the last one to be overcome is death. This is the message of the crucifixion; there is no order of difficulty in miracles. This is the message of the resurrection: Illusions are illusions. Truth is true. Illusions vanish. Only truth remains.
These lessons needed to be taught but once, for when the stone of death is rolled away, what can be seen except an empty tomb? And that is what you see who follow me into the sunlight and away from death, past all illusions, on to Heaven’s gate, where God will come Himself to take you home.”