The cube is a 3d illusion. It is 2dimensional but appears 3d. Everything in our "reality" is like this: Everything we call reality is a 3d illusion.
So we are "trapped within the cube" of illusory time. This is something I can explain at length but difficult to do while typing.
Is animal sacrifice Satanic?
Is keeping slaves Satanic?
All these things appear in the Old Testament. Is the Old Testament Satanic?
A dream is a non-physical state of experience, so yes, I do know what it feels like and yes, I can explain it to others. These concepts vastly predate Christianity. You are the New Ager here.