Orthodox Christian teaching is fundamentally at odds with belief in magick. In the middle ages the Church worked hard to get people to give up their folk superstitions about witches (belief in witches and that such witches have actual magickal power is a pagan belief, not a Christian one). Belief in witches was regarded as heresy, and witch-hunting was condemned by European rulers (most famously under Charlemagne). It isn't until near the end of the middle ages with the publication of the Malleus Maleficarum in the 15th century that opinions began to change. We associate witch-hunts with Medieval Europe, but the actual truth of the matter is that witch-hunts weren't really a thing in the middle ages, virtually all organized witch-hunts were in the early modern period, and weren't done in Catholic dominated territories, but Protestant ones. Which is why the Salem Witch Trials weren't some bizarre vestige of the medieval past, but was actually representative of attitudes of the 17th century.
The idea that Satan has god-like power and has human servants who can use such power (i.e. magick) is both heretical and blasphemous. It is ascribing to the enemy a power that, though less, no creature ever has had. The devil isn't a god, but a creature, he does not have power over the heavens and the earth, instead he is a liar, he was a liar from the beginning, and he's a liar now.
-CryptoLutheran