Kriya is in essence a love of awareness and energy within our body. The application of this love through focus, skillful means, and presence brings an inner centering and stability; awakening us as radiant light and nectar flame.
Visualizing streams of light, centering within points of effortless existence, and focusing upon subtle emotional qualities permeating space are all part of this science.
There are formal techniques to help in this unfolding using a disciplined combination of breath, rhythm, stillness, movement, visualization, lifestyle, body awareness, intention, and creativity. In time the outer kriya reveals the inner kriya, which is a very dynamic spacious freedom made of innate intelligence.
Kriya matures into the tantras, and is itself an aspect of tantra. Tantra is the grand and very intimate relationship of everything, with the important caveat of a constant timeless awareness which permeates everything.
This is the defining aspect, and true workability of the tantric unfolding from a place of innate liberation. Kriya provides a path into the pathless journey without getting lost on the way.