Hello. I am currently reading a danish translation of Saxo's "Gesta Danorum" In it he describes various tales involving the old Norse gods, however he makes sure to mention that they were not really gods but instead powerful and evil magic practitioners who were ruled from Constantinople .
My question is - was it just an invention of Saxo so that he could explain away all of his sources' mentions of gods before Christianity was adopted in Denmark or was it really what the educated elite of medieval Scandinavia believed? Do any other chroniclers mention norse (or hellenic) gods as just being extremely powerful, malicious men?
The medieval christian doctrine on magic is simple: It doesn't exist.
Saying that the nordic deities had power woud be recognizing a supernatural power other than God, wich goes against the doctrine. In the Bible, every time something supernatural happens it's either a miracle or an iilusion, like the Pharao's concillors controlling him with tricks and false clarvoyance in the tale of Moses. A real supernatural event was either an act of God, or, very seldomly, the Devil.
So when Saxo says "magic practitioners" he doesn't mean people who can do actual magic. He means illusionists. This was the orthodox belief of the educated elite. Magic isn't real, and if someone fancies himself a wizard, he is mad, a liar, misguided by superstition or in a one in a million case an actual wizard with satanic, not pagan, powers. Eroding belief in the pagan wizards of old was important, since it meant that christianity could pose as the one true faith while paganism was just bumpkins making stuff up. And since christianity had churches, elaborate rituals and infraestructure on a level the pagan faiths could only dream of, they were clear winners of the propaganda game.
That's why we today practice "pagan" acts such as hanging a horseshoe over the door or collecting shamrocks. They were degraded from religion to superstition and became so harmless the church didn't even bother erasing them.