All About Kriya Yoga
You can't talk about Kriya Yoga without talking about Mahavatar Babaji or his disciple Lahiri Mahasaya. Kirya is an ancient yoga practice that they brought to modern times. It was also given much more into the public awareness by the book Autobiography of a Yogi, written by Paramhansa Yogananda.
The Kriya Yoga system is made up of several levels of Pranayama, based on certain methods that are supposed to quickly accelerate one's spiritual development and give one an extreme state of tranquility and God-communion. According to the way that Lahiri Mahasaya has deemed, it is taught directly, from Guru to disciple.
The Kriya Yoga Practice - The Spinal Centers and Life Energy
Kriya Yoga is described as moving the life energy upward and downward, around the six specific spinal centers (these are: medullary, cervical, lumbar, sacral, dorsal, and coccygeal plexuses) which correspond to the twelve signs of the zodiac. They say that one-half minute revolving energy around the sensitive spinal cord of a man will make subtle progress in the evolution of that man; also that one half-minute of Kriya is the equivalent of one whole year of natural spiritual unfolding.
The History of Kriya Yoga
Traditionally, it is believed that Kriya Yoga was very well-known back in ancient India, but that it was eventually lost, because of to "priestly secrecy and man's indifference". There are several ancient texts that refer to Kriya Yoga, either directly mentioned by name or specifically by description of behavior. These writings talk of Kriya Yoga as consisting of "body discipline, mental control, and meditating on Aum."
More recently, in Autobiography of a Yogi, the story of Lahiri Mahasaya being initiated into Kriya Yoga by the yogi Mahavatar Babaji in 1861 is retold. According to the book, at that meeting, Mahavatar Babaji told Lahiri Mahasaya, "The Kriya Yoga that I am giving to the world through you in this nineteenth century, is a revival of the same science that Krishna gave millenniums ago to Arjuna; and was later known to Patanjali, and to Christ, St. John, St. Paul, and other disciples." The author of Autobiography of a Yogi, Yogananda, wrote, too, that Babaji and Christ were in continual communion and that together they, "have planned the spiritual technique of salvation for this age."
Lahiri Mahasaya took Kriya Yoga throughout India. Yogananda, who was a disciple of Swami Sri Yukteswar Giri (who was a disciple of Lahiri Mahasaya), then brought Kriya to the United States and Europe in the 20th century. Since that time it has spread all over the world through various Guru lineages, most of whom claim to have descended from Lahiri Mahasaya.