Comprehending the Incomprehensible.
Most religions portray their higher worlds, whether Heaven, Nirvana or whatever name its given, as reflecting this world, except with more light and clouds and whatever stereotypical depiction of Heaven exists. Likewise entertainment portrays any alien civilisations as having all of the structures, government, transports, vices and virtues etc, as this world does except with better technology. Of course there is absolutely no way that anyone in religion or entertainment could know such things, they are just projecting their own map of reality given to them by this world onto other places, if they exist.
If people want to contemplate other realities then they need to leave their maps of reality behind, as they only apply to this world and bring a blank sheet of paper instead. The worldly map of reality does nothing but blot out the new perspective of other realities and it makes people refer to it rather than the new world they are being exposed to. If anything the map of reality weighs them down like an anchor.
The thoughts, feelings, attitudes, whatever, are different and no body in their no bodies of spirit should use Earthly thoughts, feelings, attitudes, whatever, as lenses to perceive other realities, as they do nothing but cloud them. This is what it means to be pure in thought, feeling and spirit. The Kingdom of Heaven has no sinners in it therefore it is empty and if one wants to enter then he needs to become as empty as it is.
The blank sheet of paper refers to emptying one's mind of distracting thoughts, usually about this world. Become the nothing as far as this reality is concerned and prepare to start adjusting to the new reality. This new reality is extremely unclear, like coming out of Plato's dark cave and having to slowly adjust to see the new world. It's a good technique in meditation not to bring expectations into it because those expectations are usually always based on this world's map of reality. Put the map of reality away and let other places speak for themselves. They will eventually start to clear up and become more perceptible over time.
This picture is a good example of this where it shows and alchemist peering beyond the veil of this world and getting blinded which is shown by him putting his hand over his eyes.
When someone gets reborn in a religious or occult sense they effectively become like that of babies and they need to develop their senses and understanding of the world over time. As a baby all reality is a blur. It is like a slow fading ignorance that happens the more one spends in the new world.
Books like the Voynich Manuscript and Codex Seraphinanus are unable to be deciphered and one has to just refer to the pictures wondering what on Earth, or whatever reality it's taking place in, is going on. The mind wants to understand it but it is blocked from doing so and that is the beauty of these books. They are very much about comprehending the incomprehensible.
There are 3 things in Science that are incomprehensible, but which exist in non existence and have effects on things that do exists. These are Black Holes, Dark Matter and Dark Energy. These 3 things are no things and they can only really be defined by what isn't rather than what is. It is like that with trying to perceive other realities, to see them one has to become what isn't rather than what is of the body. This is what techniques such as meditation aim to do. This is what it's important not to bring the what is of this world into it.