Updated: Dec 28, 2022
Eastern religions and yoga describe Kundalini as a "mysterious life force" that keeps us alive. This explanation was enough for ancient spirituals, but for modern ones is not by far. I will give you below an explanation in modern terms as to what kundalini truly is, and what its energy serves for.
What is kundalini
Kundalini energy is actually Earth’s vital force that rises through the spine (Sushumna channel) and goes through all chakras from root chakra to crown chakra. Since we are in a 3D (D - dimension of vibration, or chakra scale) vibration world, the chakras are open just in the range of 1-10%. The root chakra where the kundalini energy resides, is open on average just 4-5%, meaning the connection with Mother Earth which maintains life in our bodies is rather weak.
Why is kundalini associated with sex?
The large majority of spirituals whether from East or West work generally in meditation mostly on the upper chakras 4 to 7 and disregard or at least invest little time if any in the inferior chakras. True that these inferior chakras are much more difficult to open than the upper ones, and they don’t bring results by far as quick as working on the upper ones. Therefore, there are lots of confusion concerning inferior chakras, including the sex subject.
Kundalini, chakras, and prana movement
The 2nd chakra (svadhistana) is dedicated to emotions, and using the kundalini energy that rises from the root chakra upwards it feeds all the organs around it including the reproductive organs that include the sexual ones obviously. Since the average 3D person on Earth is body-focused meaning that mentally he is fully attached to his own body, he couldn’t care less about the soul (subject of developing chakras 4-7). Therefore, he is rather sensitive to energy movements in the inferior chakras 1- 3 (root chakra - physical level including survival, chakra 2 - strong emotions, and chakra 3 - will, ego) which belong to the material world vibrations, and much less to the superior chakras 4 to 7 levels which are higher as vibration.
Therefore, the average person feels strongly when there is a surge of Kundalini energy, or energy coming from food, drinking, drugs, or other sources through 2nd chakra, since it overloads it and gives peak feelings, like during an orgasm.
An orgasm is actually a very short (seconds long) outburst of Kundalini energy that flashes throughout the spine from root chakra to crown chakra, and consequently unloads the root chakra and 2nd chakra of their excess energy.
This mechanism was designed in human bodies like this since one needs HUGE amounts of life-force energy to conceive a new life, it takes about 1/3 of the vital life force of a body when doing this. That’s why average people are exhausted after an orgasm.
Actually, for that few seconds or tenths of seconds of orgasm, the individual is truly “enlightened” (no thoughts, peace inside, no worries, bliss feeling, etc), but falls back immediately because his body can’t sustain this kind of energy for long, and his energy conduits are energetically clogged because of low-level food and drink he eats/drinks, and also due to the many limiting emotions in his subconscious that he harbors.
This is why energy (prana) movements in the root chakra and 2nd chakra are felt strongly by the individual since it governs sensations especially sexual ones since they drain so much energy. Since this world is 3D as vibration (3.5D actually is the average human soul and body) it is centered around the inferior chakras 1 to 3, and hence the strongest prana surges in these chakras and especially in 2nd one give the strongest sensations to people. Therefore, sex is paramount for all people and govern their life, whereas the sex subject occupies many of their thoughts. When someone undergoes a kundalini awakening the energy flow has a chance to balance inside the body and reach chakra balancing, and thus the sex impulses could decrease to an acceptable range if some adequate measures are taken.
Actually, not the sex subject is wrong by itself, ultimately it’s natural since it was coded in humans from start and serves the species' continuity; the problem is how humans handle it. For instance, some spiritual schools try to correct it like Tantra yoga, and also other more mature spiritual schools.
In the old days of India, people had no scientific background, so explanations as above would have been meaningless for them. Back then everything beyond their immediate experience was considered magic and associated with a god/goddess. Therefore kundalini (Earth's energy) was associated with the goddess Shakti and other deities and people had thus a deity to pray to and hence get an idea about what Kundalini was.
You can learn more by reading other posts in this spiritual site that are coming from a very different and fresh angle than spiritual mainstream, and based on a very long and personal experience and hands-on research, and not from books.
You might also consider a service like Psychic Readings in the Services section of this site from the ones listed here and get a spiritual diagnosis, or Healing limiting beliefs, or Compatibility for lovers, or attend my spiritual School of Body and Soul Ascension Mastery so to raise your body and soul awareness and reach into higher dimensions.