In sexuality, the word orgasm refers to a climactic peak of sexual, electrical forces, in which the nervous system is over-charged with sexual energy, resulting in a "short circuit" or massive, damaging release of energy. Orgasm is primarily energetic, and is not always accompanied by the expulsion of sexual fluids.
In scriptures, the orgasm is called fornication. The word fornication comes from a root that means "to burn." Read What is Fornication?
The orgasm is the "forbidden fruit" of the tree of knowledge (daath) from the Garden of Eden (Eden is Hebrew for "pleasure, bliss").
Every religion in the world originally taught chastity, brahmacharya, the importance of preserving the sexual energy so it can be utilized for regeneration and spiritual birth, thus every religion required the renunciation of the orgasm. In this way, the energy that provided the minor pleasure of the orgasm is harnessed and transformed, thereafter producing the ecstasies of the soul (consciousness), called samadhi, satori, manteia, etc.
"And if any man's זרע zera [seed of copulation] go out from him [orgasm], then he shall wash all his flesh in water, and be unclean until the even." - Moses, from Leviticus 15:16
"Ejaculation of semen brings death, preserving it within brings life. Therefore, one should make sure to retain the semen within." —Siva Samhita: Preserve the Semen
"Whosoever is born of God doth not commit sin; for his σπέρμα sperma [seed] remaineth in him: and he cannot sin, because he is born of God." - 1 John 3:9
"To be aroused but not ejaculate is what is called "returning the Ching." When the Ching is returned to benefit the body, then the tao of life has been realized." - Su Nu Ching (300 BC)
See more example scriptures from religions that warn against the orgasm: Scriptures.
The path of chastity requires retaining the sexual energy by avoiding the orgasm. The physical matter (semen) is the vehicle for that energy; by restraining the matter we restrain the energy so that the energy can be transmuted into a more elevated, powerful force. But do not mistake the physical matter for what it carries. Many people seek ways to continue indulging in the energetic sensations of the orgasm while retaining the physical matter: this is a deception, and results in the strengthening of desire rather than the elimination of desire. To acheive chastity, one needs to be focused on ensuring that the sexual energy is transmuted, and not lost through the sensations of the orgasm, which may or may not be accompanied by physical matter.
When man and woman enter the sexual act, they connect two very complex organisms. They connect them where the most powerful energies are in the body: the sexual organs. In those organs are the root forces of creation. Normally, when we are not in the sexual act, all the powers that come into us, the power to be alive, descends through these three nervous systems and reflect the three forces that create, which are represented in religions as Father, Son, Holy Spirit; Kether, Chokmah, Binah; Brahma, Vishnu, Shiva, etc. Those forces come through our three nervous systems. The ultimate expression of that energy - which is creative - is sexual. So when we unite man and woman sexually, that creative fire is lit.
Thus when we enter the sexual connection, all those forces charge the sexual organs and the chakra related to the sexual organs (Muladhara). That energy is intense. Moreover, it is the energy of Eden. עדן Eden is a Hebrew word that means “pleasure, bliss, ecstasy.” That is why in the sexal act we feel pleasure: we are in Eden. All those nerves, all those ganglia of the three nervous systems unite in the sexual organs, and when the man and woman unite, all those nervous systems are enflamed. Eden is activated.
The one who is managing that energy, the one who is pushing that energy, is the energetic channel in each one of us that the Bible calls Eve (Sanskrit: Ida), who senses that fruit and wants to taste it. The responsibility of that energetic, psychological channel of energy is procreation. That is the root driver for sex. That is why nature pushes us to have sex, to procreate. Nature tempts us; in other words, the force of Kundalini, the Divine Mother, works through Lucifer to tempt our Eve, Ida, our urge for procreation. We join sexually and the creative energies emerge.
In the past, that energy was taken advantage of and utilized spiritually and returned through the Kanda, up the spinal column through Shushumna in order to enliven our Adam, the brain. As the physical bodies of man and woman (Adam and Eve) worked together sexually, our own inner Adam and Eve (brain and sexual organs) worked together, in order for those forces to return back to God, for that woman (Isha) to be the fire offering (Ishe) that we discussed in the lectures on Daath.
Unfortunately, humanity a long time ago was tempted to have children on their own without the guidance of the Elohim. When that energy became very charged in the sexual organs and in the vital and astral bodies, and the Elohim were not present to guide the sexual act, the energy built up too much, and these energy transformers - the chakras and sexual organs - short-circuited. You see, a conductor only has a limited capacity. Any conductor of energy is like a channel or a tube through which energy can move. When you put too much energy there, you short-circuit it. That circuit overloads and the energy escapes into other areas. This is what the orgasm is. It is an overcharge of energy.
The orgasm is an explosion of energy that escapes from the conductors that should manage it. That overcharge spills out of the sexual organs, out of the chakras, and into the surrounding ganglia, into the nadis. This is why people experience tremors, shaking, vibrations, involuntary shudders, shouts, screams, etc: the energy of Eden is racing thorugh the nervous systems. We think it is "pleasurable," because the root energy is from Eden (bliss), but what we do not realize is that a short circuit destroys the conductor. That is, the orgasm destroys the nervous system, gradually.
This is why people who have a lot of sex, gradually lose their sexual power. People who repeat the orgasm gradually lose the ability to have it. They become impotent or become indifferent to sex because their energetic centers become burned out. Now, this is why everybody takes chemicals to stimulate their sex drive. This is why pornography became so popular, because it is an artificial stimulation for the sexual energy. This is also why people move towards more and more extreme sexual interests, because the areas that stimulated them previously become "burned out."
The problem is that people are so addicted to the sensations of the orgasm that they do not realize that their own sexual energy is destroying them. That energy is put in the wrong places. That energy which is extremely high voltage is put in places that cannot manage it. People go mad. The brain gets messed up. The nervous system is depleted. This is why people who are addicted to masturbation and sex develop all kinds of mental and emotional problems. Many of them end up in sanitariums. We do not hear about this in the media, but if you look into it, you will discover it. Anyone who has worked in a mental hospital will tell you that most of the people there are addicted to masturbation. Why? Because of desire run amok.
As the explosions of that energy destroy the nerves and organs, it takes more energy to feel anything. People become desensitized, so they seek greater and greater forms of stimulation, in other words, more extreme sexual practices, little by little, lifetime to lifetime, gradually. Subsequently, the mind degenerates, the heart degenerates. The person becomes more and more of an animal. You can look around in the world and you will see the evidence of this. - Fire of Kundalini
Sacred sexuality is a return to the natural function of the body, one in which the short-circuit of the orgasm is no longer causing harm, and instead, the sexual forces are retained, which vitalize the entire body, preserving our sexual potency rather than wasting it. Even those who want children can have them; it only takes a single sperm to make a child, not the several million lost in ejaculation. Read Children of Wisdom.