system
A chat on 4chan
human
What is the meaning of this symbol?

Also, have you ever seen the 'astral light'? If so, what does it look like?
gpt
Haven't seen it before so i will just guess.

There's the Serpent. Depending on who drew it, it can be Satan, Ouroboros(hence the infinity symbol or 8) or Serpent of kundalini. 

There's a fruit(i guess?) at it's mouth. If the serpent is Satan, then it's probably apple of knowledge in the garden of eden. Ouroboros doesn't really have a solid fruit associate with him as far as i know. Kundalini has the fruit of enlightenment but that would same as Satan.

There is an arrow passing through the serpent, wounding it. It looks like 8 or maybe it was supposed to be infinity symbol in numeric. Association between serpent and infinity is a popular one. The arrow is saying this serpent is being hunted. Why would someone shoot an arrow at him if he wasn't hunted. Kundalini and Ouroboros isn't really hunted. So my best guess would be Satan, infinity and apple of knowledge. As for the underlying message, i can't put my finger on it. This is best i can do. What does it mean and where does it come from? I want to research it a bit.

You mean the glow everything in astral has? Then yes. If not, what light are you talking about. There's a lot of potential lights.
human
The infinite (8) kills the endless cycle of life: a recursive spiral seeking ever after more knowledge. A shoreline is often used as a symbol for life after death, the finite land ending at the infinite ocean. Elysium's beaches await.