When Sri Swamiji established the Bihar School of Yoga, he developed a system of outer and inner yoga. The external yoga is known as bahiranga yoga, and the internal yoga as antaranga yoga.
External yoga is done to improve the quality of the body and mind, and the expression of the senses and behaviour. It is the effort that one makes. Internal yoga is the attitude that one cultivates and the change one brings into one's ideas and perceptions. This change is based on one's experience, understanding and one's own practice.
In the outer expression of yoga one is preparing, reconditioning and fine-tuning oneself. Once the outer expression has been managed, discipline of the body and mind has been attained, and once the emotions have been harmonized through a series of sustained practices, the mind experiences a new understanding.
With this new understanding one begins to live a harmonious, peaceful and creative life. The moment this happens, one's inner self becomes soft. It begins to experience a change in its radical behaviour in the realm of the senses and realizes its pure nature in the realm of the spirit.
The outer yoga allows one to attain the discipline of the koshas and to move from the physical to the mental and then to the spiritual dimension. Sri Swami Satyananda defined these three as bahiranga yogas: hatha yoga for body and prana, raja yoga for mind, and kriya yoga to go through the various awakenings in one's own consciousness – to experience ultimately the luminosity of the self from consciousness to spirit.
Hatha yoga is for annamaya kosha and pranamaya kosha. Raja yoga is for manomaya kosha, and kriya yoga for vijnanamaya and anandamaya kosha. These three yogas constitute the discipline which transforms human nature, the human personality and the human identity. Even if one lives these three yogas without thinking about jnana, karma or bhakti yoga, if one lives these three yogas in one's home and day-to-day life, it is enough. The appropriate, correct and sustained practice is enough. Hatha yoga, raja yoga and kriya yoga take one from point A to point E, from annamaya to anandamaya.
Once this sanyam which is external, physical, psychological and emotional has been attained in one's life, the behaviour of the mind changes. Then the natural attitude becomes purer and untainted. That natural expression of one's inner, enlightened behaviour is known as bhakti yoga, jnana yoga and karma yoga.
Therefore one has to identify with the naturalness of yoga and the naturalness of life.
—20 December 2013, Ganga Darshan, Munger, India