The physical properties of matter, this universe, enacts the ego's law of separation between cause and effect. Every single thing which happens in this universe stems from this fundamental canvas of separation.
For one thing to do something to another thing and not experience the same effects, is separation. The laws of physics even tell us that an action produces an equal but opposite reaction - not the same reaction at all but one completely different.
In this world therefore, what applies to one thing does not apply to another. There is no equality. It therefore becomes "possible" to do something in isolation in this world, and have it affect only an isolated part of the world, and perhaps not even effect the person who does it at all.
Another way to put this is that this world allows the ego to get away with murdering God. Its pictorial statement that cause is separate from effect is a statement that God has been separated from His son. It is also therefore an attack on His Son and therefore a picture of the crucifixion of His son.
The way that the ego gets away with murder, is to suggest that it is capable of doing something to God, causing God in some way, but that the effects produced by that attack affect God only, and not the ego self. Therefore the ego self "gets away with it" by separating itself off from the effects. It claims that what applies to God does not apply to you, and therefore you can produce attack without experiencing the results.
This ENTIRE UNIVERSE is set up based on this. ACIM even explicitly says this: "This world is a picture of the crucifixion of God's son." Also in chapter 27 there is an entire section titled "The picture of crucifixion" where Jesus goes into this more.
The physical universe was made by the ego to depict what it would be like for God's son to be crucified, ie murdered and attacked and rendered separate from God. To be separate from God is to be separate from Cause, and therefore cause and effect are separate in this universe, down to the subatomic particle.
Even the idea of space and time, that there could be something which applies in one place or time and not another, is an idea of the separation between cause and effect, and Jesus states in the Course that both space and time are merely beliefs. That doesn't mean you have a belief ABOUT space and time, it means space-time ITSELF is a belief in the larger mind, and is therefore an illusion.
If it were not for this entire world, this entire universe, being based on this separation from Cause, it would be IMPOSSIBLE for you do any of the things you do "in life". You could not use a knife to slice an apple - if the effects which apply to the apple apply to the knife, the apple would have to equally cut the knife. You would not be able to eat food and digest it, the food would have to eat you and digest you also.
Nothing that we call "life" in this universe would be possible without the separation of cause and effect playing out.
Now, here is a VERY important point to make. You can change your mind about this world and work on changing what seem to be your personal beliefs "about" the world, correcting your thoughts and perceptions in terms of undoing your inner belief in separation from Cause. BUT, even if you achieve that, what is to become of the physical universe?
If it persists, it IS still a picture of crucifixion. It is still a physicalized expression of an idea of death and murder. It is still being run by laws of separation and conflict. Everything that takes place in it is un-heavenly and an attack. Every way that every single object moves and interacts with other objects symbolizes and IS the belief that cause and effect are separate - which ultimately is the belief that God and His Son are separate.
You could seem to be awake in the world and yet if the world continues to govern what happens to you, if you have no apparent power to undo it or change it, if you are subject to death, if you cannot heal the sick and undo disease, if you cannot cause objects to move or to change into other objects, then you are BOUND by the laws of the ego. That's a fact.
How can this be allowed to persist, thought to be in some way holy and real, as we stay in this world, confined by this world's laws, completely governed by them, still subject to aging and DEATH, and claim that we are enlightened? There is much more to the truth than this. This world was made as an attack. That's all it was made for. You can see it as a beautiful illusion but does it undo it?
This world's fundamental functioning, it's separation-based operational laws, is precisely what we derive our egoic beliefs from. We base our logic and reasoning and beliefs and values on top of how this separation of cause and effect operates. This leads to an "automatic" ego mind which believes and THINKS just like this universe functions, as though this universe makes sense and is normal and natural and true.
And if we are to reunite cause and effect in our awareness, in our mind, then this should mean that we re-gain access to a causal power which was completely separate from us when we believed what the world shows us. Its picture of death is completely the opposite of real life.
Its claim that cause and effect are separate is a law which MIRACLES break. Miracles come to demonstrate that this world's entire foundation, the fabric of this "reality" (bullshit) is simply false and not true and not what is running the show. Miracles demonstrate that cause and effect are NOT separate, because they come from a mind where the two are one.
Miracles therefore are capable of overriding everything which arises from this world, beyond the ego's laws, and that literally means your causal power is capable of doing absolutely anything which this world would consider physically impossible.
In this world an apple is not an orange. To a miracle-worker, an apple can be turned into an orange. In this world, throwing a ball at someone's head will hurt them. To a miracle-worker, throwing a ball at their head will stop the ball mid-air and turn it into a butterfly which then lands on the person's head and kisses them. In this world when a match is taken to a flammable liquid it will ignite and explode. To a miracle-worker, the match will be cancelled out and nothing will happen, and maybe even that flammable liquid will be turned into wine.
Miracles. Miracles. Miracles. Miracles which completely DEFY absolutely every physical law and limitation, every way that one thing does something to something else against its will, and any way that one cause seems to produce an effect on something other than itself. Think you can punch Jesus in the face and knock him out and leave him with a black eye? Have a try.
The Son of God is NOT subject to this stupid illusory world and its stupid pretend laws and made-up rules and fictional regulations. Jesus tells us in the course, literally, "there is nothing you cannot do". NOTHING. NO-THING. Not just just some small things, not just some big things, not just a few slightly miraculous-seeming hints at something magical. You can literally do ANYTHING. Including moving a mountain.
Is this too far fetched? Is your mind too scary to wield such power? Are you too afraid of the potential of this, being so profoundly abundant that you can manifest anything you need at any time directly from God's unlimited supply, without having to go through stupid ego laws to slave and work hard to earn ridiculous bits of paper and metal so that you can buy what you need at a store? You are far more capable than that. BY FAR!
There is no limit. "There is nothing my holiness cannot do."