Ok, I might have to start differently by telling you what I believe, regarding body/mind, spirit and soul. I do believe these are the three components that make up our experience on Earth.
- The soul, infinite in its current form and part of the eternal source. As soul you have decided what you wish to understand, what you wish to contribute and to learn how you may best go about it on Earth. The place that still waits for us to find harmony for...but that's an even longer story...

- The spirit, the immaterial messenger between mind and soul. It is something like the phantom representation of your soul in or as your body, but the spirit is just like a hub or bridge. It does not make decisions. Yet, through it your soul sees and your mind/body receives.
- The body, your mind is just a piece of your body, like your stomach, or your hands and so on, it's "mechanical". Your body will use parts of your mind without your spirit's, nor your soul's awareness or consent. Like you may react spontaneously to some danger or any physical stimulation. At the same time your mind will translate your experience on Earth to your spirit, which is connected to your soul, as I said, like a messenger or interface.
Okay, now, your spirit is neither tied to your body, nor to your soul by a fixed force. It will detach from your body when you sleep or even if you wish to meditate and manage to do conscious astral traveling. You may notice this detachment in your sleep, if you have a lucid dream.
Dreams come in different ways and take you to different places for reasons your spirit chooses. I believe, while your body sleeps, your spirit begins to work through your experiences of the day, or whatever inspired or troubled your mind. It may even be in communication with your soul during that time and it will take you to places that help make sense of what your mind has to receive from your soul. Like if you feel like there's something "you wanted so much", but your mind somehow did not allow you to pursue it. Or there's something you weren't ready to explore enough and your soul send your spirit to places that help you understand and gain the courage.
Nightmares may be when your mind is not willing to accept what is being shown to it, who knows for sure. Not to mention that there are infinite possibilities for why we get to see something or experience something within dreams. But I do believe that your spirit actually goes there and it can be as real as it feels, even if the consequences manifest very differently here on Earth. They do in form of your actions on Earth. Dreams influence your decisions. That's the whole point.
So, yes, they are VERY important! And it is magical, even if sometimes scary, to realize what freedom you truly have and what privilege it is to use this freedom of your spirit and your soul in a realm without any permanence in form to take inspiration and bring some permanence to it in this world we all share. Your visions and your creations allow us to get a piece of your spirits journey and the beauty of your soul!
