By Robert Mortem
A demonic sigil is a seal, sign or character by which one can conjure a demon. There are various forms of sigils, both in both ceremonial and chaos magic. The seal itself functions somewhat as a portal, and can be written down in certain cases or engraved (e.g. into a candle). This may sound odd to the average deceived person (hylics), but even languages and alphabets channel knowledge via letters and sentence structure. Scientifically, this is certainly feasible therefore. One can acquire an entire message via words in writing. Elementally, demons can likewise be channeled through specific sigils, and that with specific knowledge (e.g. the demon Orobas).
Aside from a channeling sigils, there are no doubt protection sigils (which can even used as a sacred talisman). With noble demons, come chaotic and tumultuous demons (πονηρὸν δαιμόνιον). Many are confused into thinking that all demons are "evil", but that is far from the truth. The Greek Magic Papyri mentions the Agathos Daimon (PGM IV. 1596) which can literally be translated good demon. This notion of dualism is referred to in the Ars Theurgia, as it says: "These are by nature good and evil, that is the one part is good & the other part is Evil." Pretty straight forward, and somewhat like a coin. As the Grimorium Verum says: "Whoever makes a friend his superior, makes himself an enemy." It is no wonder the Babylonians would wear Pazuzu as a protection amulet, yet nonetheless identified him as the spirit of the southwest winds and plagues.
An example of a more obvious protection sigil would of course be the upright pentagram, whereas something like a dorje (Tibetan) can be used as an amulet object (or talisman). This is the same sort of concept, and intended to ward off evil spirits and bad energy.
Although there are many different traditions of demonic sigils (the Ars Goetia being very popular), intent will play its part in regards to the authenticity of the matter. As the Verum says, the spirits act easily, "provided they are content with the operator." In other words, there is more to magick than merely drawing a sigil. Moreover, are the Ars Goetian demons of a "Christian" origin? Absolutely not, although some may be deceived into thinking along those lines. For instance, Bael (Baal) stems from the Baal Cycle tablets, which is Ugaritic and stems from paganism (Canaanite). The demon Asmoday stems from Aeshma (Aēšma-daēva) which is initially Persian (Zoroastrianism). Amon comes from the Egyptian deity Amun; Belial is derivative of Belili (Mesopotamian). It's amazing how people at times result to anachronism. To speak of these demons as Christian is simply to read backwards, as they are all initially pagan.