A regimen is necessary when you are dealing with the organisation of the subtler matter of the astral and mental worlds, for you cannot build up your physical body out of the coarser combinations of matter on the physical, and have finer combinations on the astral and mental.

The bodies have to match each other.

They have to correspond with each other; and as you find all sorts of combinations related the one to the other on every plane, you must choose your combinations on the physical if you desire to choose them also on the astral and mental.

You cannot make your physical body coarse, and organise the astral and mental bodies for the finer purposes of the man; and you must settle that in your minds if you wish to try to develop these higher powers of consciousness.

Not only because if you gather together the coarser materials of the astral world, you will find yourself hampered by them in the higher expression of consciousness, but also because the presence of these combinations in you exposes you to a number of dangers on the astral plane.