Kundalini and Kundalini Shakti are Sanskrit terms for the primordial life-force or universal energy as it functions in the human body-mind. The closest Western term would be Holy Spirit. The arousal and release of this latent power in the course of meditation or devotional prayer, etc., is what Western mystics call “spiritual baptism.”
This spontaneously occurred in my case in 1993 when I was 41. For the next eight months the Kundalini took me on a tour of the subtler dimensions of the whole body-mind. Entirely unbidden (and for the first time in my 22-year meditation practice), I began having visions.
In my lucid visions, the upward- and downward-pointing interpenetrating triangles, formed of brilliant light, stood in space before my inner eye, with my seated form (in lotus-posture) fitting inside the mandala star. I understood bodily that this archetype expresses the harmonized fullness of the ascending and descending currents of the life-force (kundalini shakti).
Oh, and here is Vajrayogini herself in all her allegorical, metaphorical splendor: