My Answer: Heaven is the feeling of fulfilling another person. This is the state of the Creator, the force of bestowal and love that rules over all of nature. If this force reveals your opposition to it, then you feel hell, and if this force is expressed directly, then you experience a sensation called heaven.
Every state we go through includes all the possible states because everything consists of ten Sefirot. Therefore, heaven and hell, as well as all five worlds, include all the states. Otherwise it would be impossible to perceive them. A baby, for example, consists of all the same parts as an adult, even though he has no need for his legs yet.
Right now I perceive the world within my five senses: smell, taste, touch, vision and hearing. All information enters me through these senses and is united in my subconscious, which creates the picture of the world that I see. As a result, I perceive myself – a sensation that comes mostly from the sense of touch, which causes me to feel external and internal pressure on my body. Besides this, I experience myself and the world around me through hearing, vision, taste and smell. To the degree that my desires increase or wind down, I experience myself in different states.
When my desires become more revealed, I begin to feel the influence of the surrounding world. But in reality, the external world does not exist; it is my own desires that are divided into internal and external ones. More specifically, they are divided into five levels: Shoresh, Neshama, Guf, Levush, and Heichal (root, soul, body, clothing, and castles). Alternatively, they can be called Keter, Hochma, and Bina (which are my inner desires), and Zeir Anpin and Malchut (these are the external desires).
In my inner desires (root, soul, and body) I feel myself. The desires called clothing and castles are also my desires, but ones that I am unable to bring closer to me and to absorb; I cannot attach them to myself so firmly that they will be inside me. This is why it seems to me that the entire world exists around me. “Clothing” refers not just to clothing, but to anything that is outside of me yet close to me, whereas “castles” refers to the entire rest of the world, which is more distant from me.
However, this entire division exists only in my perception. If I correct my desires so they all unite inside me, bound by one screen (one anti-egoistic action), then I will find that the entire universe is inside of me. I will no longer feel as if there is something taking place or existing outside of me.
The sensation that I live in an enormous, spacious and multi-faceted world comes from the fact that my desires are uncorrected. After all, I live inside my desire, since it was the only thing created by the Creator.