What is Kriya Yoga?
Since you have mentioned in another question that you are reading Autobiography of a Yogi, I do not want to play spoiler. The information is contained in the same book.
What is Kriya Yoga?
Kriya Yoga is a yogic meditation technique by which the senses, body, mind, all come under the control of the seeker.
Paramahansa Yogananda describes Kriya Yoga:
The Sanskrit root of Kriya is kri, to do, to act and react; the same root is found in the word karma, the natural principle of cause and effect. Kriya Yoga is thus "union (yoga) with the Infinite through a certain action or rite." A yogi who faithfully follows its technique is gradually freed from karma or the universal chain of causation.
He says that Patanjali also refers to the same or a similar technique in His Yoga Aphorisms:
Kriya Yoga is mentioned twice by the ancient sage Patanjali, foremost exponent of yoga, who wrote: "Kriya Yoga consists of body discipline, mental control, and meditating on Aum." Patanjali speaks of God as the actual Cosmic Sound of Aum heard in meditation. Aum is the Creative Word, the sound of the Vibratory Motor. Even the yoga-beginner soon inwardly hears the wondrous sound of Aum. Receiving this blissful spiritual encouragement, the devotee becomes assured that he is in actual touch with divine realms.
So in other words, Kriya Yoga is a kind of meditation and Yoga technique focusing on Self Discipline, Pranayama, and Meditation.
What is the main purpose of Kriya Yoga?
The purpose of Kriya Yoga, like any other 'Yoga', is in the meaning of the word Yoga. Yoga means Divine Union. In other words, union with God. Kriya Yoga has as its goal the union with God.
Paramahansa Yogananda says about Kriya Yoga:
In the initial states of God-contact (savikalpa samadhi) the devotee's consciousness merges with the Cosmic Spirit; his life force is withdrawn from the body, which appears "dead," or motionless and rigid. The yogi is fully aware of his bodily condition of suspended animation. As he progresses to higher spiritual states (nirvikalpa samadhi), however, he communes with God without bodily fixation, and in his ordinary waking consciousness, even in the midst of exacting worldly duties.
So in other words, the goal is to obtain that peerless state called as Samadhi where the seeker comes in contact with God or Brahman.
How is Kriya Yoga different from other Yoga?
So There are basically four classifications of Yoga
- Bhakti Yoga (Path of devotion to God)
- Jnana Yoga (Path of Wisdom)
- Karma Yoga (Path of Action)
- Raja Yoga (The Royal Path)
Kriya Yoga is a type of Raja Yoga. Here is some information about Raja Yoga:
Swami Sivananda describes Raja Yoga:
Raja Yoga is the king of Yogas. It concerns directly with the mind. In this Yoga there is no struggling with Prana or physical body. There are no Hatha Yogic Kriyas. The Yogi seats at ease, watches his mind and silences the bubbling thoughts. He stills the mind, restraints the thought-waves and enters into the thoughtless state or Asamprajnata Samadhi. Hence the name Raja Yoga. Though Raja Yoga is a dualistic philosophy and treats of Prakriti and Purusha, it helps the student in Advaitic Realization of oneness eventually. Though there is the mention of Purusha, ultimately the Purusha becomes identical with Highest Self or Purusha, or Brahman of Upanishads. Raja Yoga pushes the student to the highest rung of the spiritual ladder of Advaitic realization of Brahman.
The Self-Realization Fellowship describes Kriya Yoga:
Kriya is an advanced Raja Yoga technique of pranayama (life-energy control). Kriya reinforces and revitalizes subtle currents of life energy (prana) in the spine and brain. The ancient seers of India (rishis) perceived the brain and spine as the tree of life. Out of the subtle cerebrospinal centers of life and consciousness (chakras) flow the energies that enliven all the nerves and every organ and tissue of the body. The yogis discovered that by revolving the life current continuously up and down the spine by the special technique of Kriya Yoga, it is possible to greatly accelerate one's spiritual evolution and awareness.
Can anyone learn Kriya Yoga?
Kriya Yoga being a type of Pranayama and Kundalini Yoga, is very dangerous and risky, if not done right.
Any form of Pranayama and Kundalini Yoga, Kriya Yoga, etc. have to be learned from a qualified teacher. The one who attempts to do it at home by reading a book or watching a TV show is taking a big risk of harming himself.
Paramahansa Yogananda describes this briefly:
Because of certain ancient yogic injunctions, I cannot give a full explanation of Kriya Yoga in the pages of a book intended for the general public. The actual technique must be learned from a Kriyavan or Kriya Yogi; here a broad reference must suffice.
Thus these points in the answer are only an information and they MUST NOT BE attempted without proper initiation into Kriya Yoga. As long as there is a burning desire for Self Realization, the path (Karma, Jnana, Bhakti, Raja) will unfold by itself. All paths are One.
Ekam Sat Viprah Bahuda Vadanti. [Rig Veda, 1-164-46]
The Truth is One, Sages call it by different Names.
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