Okay lets get back on topic:
One interesting way to view the astral plane is to compare it to what the greeks thought about the soul.
They divided the self between three levels ; body, mind and spirit. The mind could be "connected" in some sense to the body or the spirit. When the mind was connected to the body then the person was a materialistic one or was not open to divine enlightenment, something like that. An 'enlightned' or 'annointed' person would be a person who had its mind connected to the spirit. The astral plane is the mind when it is connected to the body in the greek description above.
And just as a curiosity, the concept of holy spirit is associated to this. As many people know the holy spirit has its origins from the greeks. The holy spirit will be the mind when it is connected to the spirit, thats why the holy spirit is associated to the manifestation of God within oneself. Someone is 'annointed' or 'enlightned' when she/he have the holy spirit.
That is what chirst means too, it comes from the greek word 'chrestos' what means exactly 'annointed'.