Priya Nath Karar was born in Calcutta, India to a family that was God-conscious. The intelligent boy grew up with interests in various subjects including medicine, astronomy and astrology. He had mastered various languages and was always in quest of learning more.
Priya Nath Karar was initiated by Lahiri Mahasaya into the monastic order and was thence known as Swami Sri Yukteswar. It was during the meeting of Yukteswar with Mahavatar Babaji, the guru of Lahiri, that he was asked to write a book explaining the similarity that exists in the scriptures of Hinduism and Christianity. His book, which is originally titled "Kaivalya Darsanam," shed light on the similarities between the scriptures of the Bhagavad Gita and The Bible. The purpose of the writing was to emphasize that all faiths are one in essence.
Swami Sri Yukteswar was the founder of Yogoda Satsanga Society of India, also known as the Self-Realization Fellowship (SRF) in the West, which aimed at creating awareness among people and helping society to be harmonious. He formed several SRF centers in India and his disciple, Yogananda, followed his footsteps to set up the first SRF of its kind in the United States.
Yukteswar was bestowed the title Gyanavatar, meaning "divine incarnation of wisdom," by Yogananda who spread the essence of kriya yoga in the West. Kriya yoga refers to the yoga system revived by Mahavatar Babaji aiming at spiritual progress through advanced techniques.