“Tantra(Sanskrit: तन्त्र), also called Tantrism and Tantric religion, is an ancient Indian tradition of beliefs and meditation and ritual practices that seeks to channel the divine energy of the macrocosm or godhead into the human microcosm, to attain siddhis and moksha. It arose no later than the 5th century CE, and it had a strong influence on both Hinduism and Buddhism.
Maithuna (Devanagari: मैथुन) is a Sanskrit term used in Tantra most often translated as “sexual union” in a ritual context. It is the most important of the five makara and constitutes the main part of the Grand Ritual of Tantra variously known as Panchamakara, Panchatattva, and Tattva Chakra.
Mithuna, Lakshmana Temple, Khajuraho, Madhya Pradesh, India.
Although some writers, sects and schools, e.g. Yogananda, consider this to be a purely mental and symbolic act, a look at different variations (and translations) of the word maithuna clearly shows that it refers to male-female couples and their union in the physical, sexual sense and is synonymous with kriya nishpatti (mature cleansing). Just as neither spirit nor matter by itself is effective but both working together bring harmony so is maithuna effective only then when the union is consecrated. The couple become for the time being divine: she is Shakti and he is Shiva. The scriptures warn that unless this spiritual transformation occurs the union is carnal and sinful.
Yet it is possible to experience a form of maithuna without physical union. The act can exist on a metaphysical plane without sexual penetration, in which the shakti and shakta transfer energy through their subtle bodies alone. It is when this transfer of energy occurs that the couple, incarnated as goddess and god via diminished egos, confronts ultimate reality and experiences bliss through union of the subtle bodies.
In Hinduism, Shakti (Devanagari: शक्ति; from Sanskrit shak, “to be able”), also spelled as Sakthi, meaning “power” or “empowerment” is the primordial cosmic energy and represents the dynamic forces that are thought to move through the entire universe. Shakti is the concept or personification of divine feminine creative power, sometimes referred to as ‘The Great Divine Mother’ in Hinduism. As the mother she is known as Adi Parashakti or Adishakti. On the earthly plane, Shakti most actively manifests through female embodiment and creativity/fertility, though it is also present in males in its potential, unmanifest form.
Hindus believe that Shakti is both responsible for creation and the agent of all change. Shakti is cosmic existence as well as liberation, its most significant form being the Kundalini Shakti, a mysterious psychospiritual force.
In Shaktism and Shaivism, Shakti is worshipped as the Supreme Being. Shakti embodies the active feminine energy of Shiva and is identified as Tripura Sundari or her avatar Parvati.
At the highest level, Shiva is regarded as formless, limitless, transcendent, and unchanging as well. Shiva also has many benevolent and fearsome depictions. In benevolent aspects, he is depicted as an omniscient Yogi who lives an ascetic life on Mount Kailash, as well as a householder with wife Parvati and his two children, Ganesha and Kartikeya, and in fierce aspects, he is often depicted slaying demons. Shiva is also regarded as the patron god of yoga, meditation and arts”