The same book says:
"The student should know that in the astral sheath surrounding the physical body—this is the coarser envelope of
passion and desire—his lower thoughts attract intelligences of an evil nature to its fluidic and translucent substance, and
there derange the mental body by impressing their thoughts into it, so weaken the character thus assailed. These spirits can
foretell many interesting things and give us secret information in order to bind us to them; though there is little of real worth
in such. Their astral fluids emit a very disagreeable odour; for they secrete and are nourished upon diseased forms of matter
that we throw off...
"MAN has brought over the astral sheath from a remote past, and, like the foetus in its early stages, it represents man’s past submerged worlds of consciousness. If the student immerses himself in its atomic structures it will revert him to his lower passions and desires. It is through Yoga practice that we free ourselves from its domination."
M uses the word astral to refer to the body of desires related to our defects. This is the lower or inferior astral world.
Samael Aun Weor recommends that we learn how to extract ourselves from that aspect, and consciously enter the superior astral world.
"Do not worry; cultivate the habit of being happy." - Samael Aun Weor