The pentagram was first used by Mesopotamians in approximately 3000 BC. In the Babylonian context, the edges of the pentagram were probably orientations: forward, backward, left, right, and “above”. These directions also had an astrological meaning, representing the five planets Jupiter, Mercury, Mars and Saturn, and Venus as the “Queen of Heaven” (Ishtar) above. The Pythagoreans called the pentagram Hygieia (meaning “health”; also the Greek goddess of health, Hygieia), and saw the pentagram to represent mathematical perfection. The five vertices were also used by the medieval neo-pythagoreans (whom one could argue were not pythagoreans at all) to represent the five classical elements of earth, water, air, fire and spirit.
The inverted pentagram was used by the Jews, and sometimes referred to as the seal of Solomon. The inverted pentagram was used as the seal of the City of Jerusalem, as early as the 4th Century BC.
The (non-inverted) pentagram was also in use by the Knights Templar (e.g. on gravestones)
Heinrich Cornelius Agrippa von Nettesheim (1486-1535) was a German magician, occult writer, astrologer, and alchemist, who first popularised the pentagram in the Western European Occult context. He used the pentagram (aka pentacle) in both the ‘regular’ and ‘inverted’ forms.
Medieval Christians believed the pentagram to symbolise the five wounds of Christ. The pentagram was believed to protect against witches and demons (the application of the pentagram is similar to that of Occultists who use it as protection against spirits during invocation and banishing rituals) , e.g. The painting ‘Christ as a Pentagram’, from Valeriano Bolzani’s Hieroglyphica (Basel, 1556)
The inverted pentagram was adopted by Mormonism from the 1830s to 1840s.
Albert Pike stated that the Pentagram was synonymous with the Blazing Star of Masonic Lodges.
It has also been adopted by the Baha’i faith as its symbol.
The inverted pentagram was adopted by Anton LaVey and the Church of Satan in 1966 (with the Eliphas Levi’s Baphomet), the downward pointing vertices representing opposition to the Trinity. It is also used by the vast majority of Theistic Satanists of various types.
The pentagram was adopted by many neo-pagans, especially Wiccans, as a symbol of faith.
By the mid-19th Century, a further distinction had developed amongst occultists regarding the pentagram’s orientation and usage. With a single point upwards it depicted spirit presiding over the four elements of matter, and was essentially ‘good’. The inverted pentagram was considered ‘evil’.
In his 1855 book Transcendental Magic, its Doctrine and Ritual, Eliphas Levi wrote:
“A reversed pentagram, with two points projecting upwards, is a symbol of evil and attracts sinister forces because it overturns the proper order of things and demonstrates the triumph of matter over spirit. It is the goat of lust attacking the heavens with its horns, a sign execrated by initiates.”
The pentagram was first used by the Hermetic Order of the Golden Dawn, a Rosicrucian/Theosophist Freemasonry Offshoot, probably sometime between 1888-1892. This usage and application of the pentagram for invocation and banishing rituals has been widely adopted by Thelemists, Neo-Pagans, Theistic Satanists and LaVey Satanists later in the 20th Century…
(excerpt from: http://www.detoxorcist.com/history-of-pentagram.html
All associations, historical specificity, and meanings espoused here are of the author, not necessarily my own. interlocutor-slabbb-)