Question: Does the soul stay always with the same body from birth, or does it sometimes leave the birth-body before physical death to allow a more advanced soul to take over the body to complete a special mission?

Sri Chinmoy: While on earth, the soul remains in the body. When the soul finally leaves, the body dies. During the course of our lifetime, the soul usually leaves the body only for a few minutes at a time. Definitely the soul leaves many, many times to visit other souls or other human beings. Each person's soul goes to visit other persons, but more than eleven hours if the soul remains outside the body, there is a serious danger that the soul may not be able to come back into that body.