Sanatan Kriya, as formulated by Yogi Ashwini, encapsulates in its entirety, all the eight limbs of Ashtang Yoga as prescribed by the Patanjali Yoga Sutras about 5000 years ago.
The eight limbs of Ashtang Yoga are - Yama, Niyama, Asana, Pranayam, Pratyahar, Dhyan, Dharna, Samadhi.
By following the practice of the five Yamas and five Niyams, the path of Yoga becomes clear. The impediments in the progress of the practitioner or sadhak get removed leading the sadhak to the next stage, which involves the purification of the physical and the etherical self of the individual.
Asana is a posture, which is attained with the objective of gaining mastery of the physical body. The practitioner or more appropriately the sadhak practices the posture with complete awareness of the physical and internalization of senses till the posture becomes effortless or in other words till the physical is completely mastered.
This internal awareness leads to activation of every cell of the physical body thereby cleansing the physical body of any disease or discomfort. The sadhak attains a healthy physical body, helping him or her to move further in the spiritual practices. A sadhak who has perfected the asanas does not have to bother about the discomforts, aches or pains of the physical body, which a normal human being is afflicted with. His consciousness is so heightened that through awareness he/she removes physical ailments and discomforts
Pranayam is the practice of gaining control over the next layer of the being, which controls the physical layer. This layer called the Pranamaya Kosha, is our etheric self and from here starts the world of the Spirit. This layer comprises of various colours of the spectrum and millions of shades within each colour. It is these colours, which govern each and every aspect of our physical. Clairvoyants are people who have the ability to see these colours and also understand the impact of these colours on the physical. The practice of pranayam helps the sadhak gain mastery on this etheric layer, through which it becomes simpler to send instructions to the Annamaya Kosha. This layer directly controls Annamaya (the physical body).
Only once one has gained control over the physical and the etherical can one proceed to the next stage of Pratyahar that is when you learn to withdraw the five senses inwards. Till the time the sadhak is affected by the physical and the factors influencing it, it is not possible to control the senses. Then comes the next stage - Dharna, which is the stage when you have one single aim, the aim to achieve the ultimate i.e. the samadhi or to be in Yoga with yourself or Atma Sakshatkar.
After all this actually comes the state of Dhyan. Dhyan is going back in time when there was nothingness, when there was nothing physical, there was just you as pure consciousness. Dhyan is a state, which is higher than the present moment's state and keeps us taking closer to the source with regular practice. You do not achieve but enter into the state of dhyan. However, this state can be entered into when you have full control on your physical and emotional self and the external and internal disturbances have died down.
Finally comes the state of Samadhi. Samadhi is a state to be experienced and not to be discussed. So the process of awakening is a subject of continuous and dedicated practice leading the sadhak from one dimension to the other till Yoga is achieved.