A Treatise on the Seven Rays:

Death itself is a part of the Great Illusion, and only exists because of the veils we have gathered around ourselves.
- Vol. V.

A Treatise on White Magic:

But people are apt to forget that every night in the hours of sleep we die to the physical plane and are alive and functioning elsewhere. They forget that they have already achieved facility in leaving the physical body; because they cannot as yet bring back into the physical brain consciousness the recollection of that passing out, and of the subsequent interval of active living, they fail to relate death and sleep. Death is, after all, only a longer interval in the life of physical plane functioning; one has only "gone abroad" for a longer period. But the process of daily sleep and the process of occasional dying are identical, with the one difference that in sleep the magnetic thread or current of energy along which the life force streams is preserved intact, and constitutes the path of return to the body. In death, this life thread is broken or snapped. When this has happened, the conscious entity cannot return to the dense physical body, and that body, lacking the principle of coherence, then disintegrates.
- Page 494.

A Treatise on the Seven Rays:

The processes of abstraction are (as you may thus see) connected with the life aspect, are set in motion by an act of the spiritual will, and constitute the "resurrection principle which lies hidden in the work of the Destroyer," as an old esoteric saying expresses it. The lowest manifestation [445] of this principle is to be seen in the process of what we call death - which is in reality a means of abstracting the life principle, informed by consciousness, from the form of the bodies in the three worlds.
Thus, the great synthesis emerges and destruction, death, and dissolution are, in reality, naught but life processes. Abstraction is indicative of process, progress and development. It is this aspect of the Law of Life (or the Law of Synthesis as it is called in certain larger connotations) with which the initiate specifically deals.
- Vol. V.

Life is approached from the angle of the Observer, and not from that of a participator in actual experiment and experience in the three worlds (physical - emotional - mental)...if they are initiated disciples they are increasingly unaware of the activities and reactions of their personalities, because certain aspects of the lower nature are now so controlled and purified that they have dropped below the threshold of consciousness and have entered the world of instinct; therefore, there is no more awareness of them than a man asleep is conscious of the rhythmic functioning of his sleeping physical vehicle. This is a deep and largely unrealized truth. It is related to the entire process of death, and might be regarded as one of the definitions of death; it holds the clue to the mysterious words "the reservoir of life." Death is in reality unconsciousness of that which may be functioning in some form or another, but in a form of which the spiritual entity is totally unaware. The reservoir of life is the place of death, and this is the first lesson the disciple learns...
- Vol. V.