For your reference, I am pasting here the definition of Kriya Yoga from Autobiography of Yogi:
Kriya Yoga is a simple, psychophysiological method by which the human blood is decarbonized
and recharged with oxygen. The atoms of this extra oxygen are transmuted into life current to rejuvenate the brain and spinal centers. By stopping the accumulation of venous blood, the yogi is able to lessen or prevent the decay of tissues; the advanced yogi transmutes his cells into pure energy.
Kundalini is the energy responsible for evolutionary development and heightened states of consciousness and awareness, and is present in all living forms of life. All forms of life are growing towards increasing levels of self-awareness. Though there are certain techniques / practices existing for raising the Kundalini, it depends more on the individual's spiritual evolution.
Thanks HariKrishna
Kriya is a evolutionary quickening technique. Kriya (or similar techniques) brings the life energy, or pranayama, back to the spine and starts awakening the Kundalini. This further awakens the chakras and raises the energy back up the spine to awaken the higher centers. Eventually this process brings higher states of consciousness, spiritual awakeing and experiences until ultimatly the soul merges again into the vast ocean of God's consciousness: merging back into the infinite.
i think what is interesting about this technique is to actually see it working to see the energy withdrawing from the senses and the body being as if dead and the spirit coming to life. As saint Paul said: "I protest by my rejoicing in Jesus Christ. I die daily." and in Revelation: "Be still and know that I am God" and in the Old Testament: Moses lifted up the serpent (Kundalini) in the wilderness (being alone).
Steve Hydonus