From his book Being Evolution and Immortality
Finally, the concept of immortality implies a harmonization of the entire
personality and a transformation of the physical organism as an effective
channel of expression of higher values. This may be called material
immortality (rupantar mukti).
There are some mystics and spiritual seekers who strengthen and purify their bodies just enough to be able to experience the thrilling touch of the Divine. They use the body as a ladder, by climbing which the pure spiritual level - the domain of immortality - is to be reached. On attaining that level, the body is felt as a burden, as a prison house, as a string of chains that holds one in bondage. Dissociation from this last burden of the body is considered a sine qua non for total liberation. Continued association with the body is believed to be the result of the residual trace of ignorance ( avidya lesa). When the residual trace of ignorance is gone, the spirit is set free from the shackles of the body.
The above view is based upon a subtle misconception about the purpose of life and the significance of the body. The body is not only a ladder that leads to the realm of immortality, but also an excellent instrument for expressing the glory of immortality in life and society. It is capable of being thoroughly penetrated by the light of the spirit. It is capable of being transformed into what has been called the "Diamond Body." As a result of such transformation, the body does not appear any more to be a burden upon the liberated self. It shines as the Spirit made Flesh. It functions as a very effective instrument for creative action and realization of higher values in the world. It is purged of all inner tension and conflict. It is liberated from the anxiety of repressed wishes. It is also liberated from the dangerous grip of the death impulse born of self-repression. Mystics who look upon the body as a burden suffer from the anxiety of self-repression and the allurement of the death wish.
Material immortality means decisive victory over both of these demons. It conquers the latent death instinct in man, and fortifies the Will to live as long as necessary, as a channel of expression of the Divine. It also liquidates all forms of self-suppression and self-torture and self-mutilation. As a result the total being of an individual becomes strong and steady, whole and healthy. There is a free flow of psychic energy. It is increasingly channelled into ways of meaningful self-expression. Under the guidance of the indwelling light of the Eternal, it produces increasing manifestation of the Spirit IN Matter.