Every person in Sai's Divine mission is an instrument chosen by Swami Himself. Mother Easwaramma was the 'Chosen' mother of Bhagawan Sri Sathya Sai Baba. It can also be said that Prof. N. Kasturi was His chosen biographer. V. K. Narasimhan, who then took-over the reins as the editor of 'Sanathana Sarathi', described him as Swami's Vyasa.
In the initial phase of the Avatar, Sri Kasturi was solely responsible for translating Swami's Discourses, noting down, and then publishing Sai literature, thereby propagating Swami's Life and Teachings to the entire humanity.
Swami chose him as His instrument to gift mankind these Divine pearls of Sai's teachings and the Life story of Bhagawan. Apart from Swami's Discourses, which were translated by Kasturi himself, and other teachings, Prof. Kasturi was also a witness to the innumerable miracles of Swami at various places, wherever Swami went and Sri Kasturi was blessed to accompany and witness the same.
Sri N. Kasturi, born on Christmas day of 1897, served Swami for 40 years till his death in the year 1987, at the age of 90. He was cremated on the banks of the river Chitravathi on India's Independence day (15th August, 1987). A life dedicated to the Divine mission.