This is one of those myths that stems from other religions’ fear and misunderstanding of the Pagan path. Particularly among Christians, it’s thought that magic is evil, and anything that doesn’t come from God must come from the Devil or his minions, namely demons.
Since Pagans don’t believe in Satan, and those who believe in demons see them as something very different from what other faiths do, they obviously don’t think that their power comes from that source. Pagans believe that magic comes from the Gods, earth, the universe itself. It is pure in nature and free to be used by anyone with the skill and desire. It is not evil, nor does it come from an evil source.
Pagans don’t even commune with demons or other evil entities as a general rule. They cast a circle of protection to keep dark forces out of their workings, they don’t invite them in! Now, keep in mind that many Pagans do believe it is entirely possible to call on “dark” forces or entities and have them aid the practitioner in their magick. However, it’s not something anyone would do, unless they’re willing to face the consequences of such an act, or are very foolish. If anyone ever said they were going to try to contact or work with a demon, every sane Pagan around would be trying to talk them out of it.
As a side note, Daemons (the origin of demon) are spirit guides and in ancient cultures were considered a good thing to call upon for aid. Christianity turned the term into something evil.
*Disclaimer: I no longer practice Paganism, but I’ve left these Pagan Myths articles active because I believe they’re still valuable in helping people to understand Paganism and reduce negative stereotypes.*